Dec. 18 – Tehran signed the Additional Protocol to the Non-Proliferation Treaty’s Safeguards Agreement. The Additional Protocol granted IAEA inspectors greater authority in their nuclear verification programs. Since then, Iran has at times voluntarily allowed more intrusive inspections, but the Iranian parliament has not yet ratified the Additional Protocol.
Aug. 11 –The IAEA urged Iran to suspend all enrichment activities and re-instate IAEA seals.
March 26-April 2 – Iran and the P5+1 met in Lausanne, Switzerland in the final days before the deadline for a political framework. Kerry and Zarif held bilateral discussions, and negotiators from Britain, China, France, Russia, and Germany joined the talks on March 28.
Jan. 16 – Iran and the P5+1 marked the nuclear deal's Implementation Day after the IAEA confirmed that Iran has taken the necessary steps to start implementation of the nuclear deal. The United States, European Union, and United Nations lifted or suspended certain sanctions. Iran also regained access to the international financial system, repatriated billions of dollars in frozen assets abroad, and returned to the oil market.
Feb. 26 – The IAEA announced in a report that Iran briefly exceed the amount of heavy water it was allowed to have under the JCPOA by 0.9 tons. The U.N. nuclear watchdog also stated that Iran had rectified the issue by shipping 20 tons of heavy water one week after the limit was exceeded. Heavy water is used in certain types of nuclear reactors that can produce weapons-grade plutonium.
April 22 – The United States agreed to purchase 32 tons of heavy water from Iran. Under the JPCOA, Iran was required to keep its stocks of heavy water under 130 tons.
May 5 – AEOI Chairman Ali Akbar Salehi and IAEA Director General Yukiya Amano met in Tehran to discuss the implementation of the JCPAO.
May 27 – The IAEA released a report that stated Iran was in compliance with its obligations under the JCPOA.
July 12 – U.N. Secretary General Ban Ki-Moon released his first biannual report to the UN.. Security Council on the implementation of U.N. Security Council Resolution 2231 (2015), which endorsed the JCPOA, addressed JCPOA implementation, and reviewed other U.N. sanctions on Iran. The report found Iran was implementing its JCPOA obligations, but expressed concern over reports that Iran had violated arms transfer restrictions, ballistic missile activity restrictions, and restrictions on the travel of sanctioned individuals.
July 29 – Iran submitted a letter to the IAEA complaining about a leaked confidential document. The document, which the Associated Press reported on, indicated that certain key nuclear restrictions on Iran would be eased prior to the general 15-year expiration date of the deal. The IAEA denied that it had leaked the document.
Sept. 8 – The IAEA’s report found that Iran was in compliance with its obligations under the JCPOA.
Sept. 10 – Iran began construction on its second nuclear power plant with Russian help, the first such project since the final nuclear deal. The project in Bushehr included two plants and was slated to come online in 10 years.
Nov. 9 – The IAEA released a report that found Iran to be in general compliance with the JCPOA, although its heavy water stocks had exceeded the limit by 0.1 tons. Iran informed the IAEA that it was planning to ship five tons out of the country.
Dec. 13 – In response to the renewal of the Iran Sanctions Act by the United States, President Rouhani announced that Iran would begin work on nuclear-powered marine vessels. He said fuel production would be “in line with the development of a peaceful nuclear program of Iran.” But nuclear experts said that such fuel would likely require enrichment beyond the limits set by the JCPOA. Iran previously announced it was working on a nuclear-powered submarine in 2012.
Dec. 30 – U.N. Secretary General Ban Ki-Moon released his biannual report to the U.N. Security Council on the implementation of U.N. Security Council Resolution 2231 (2015). The report confirmed Iranian compliance with the JCPOA, but raised concerns about reports of Iranian arms transfer violations and the travel of sanctioned individuals, in violation of Resolution 2231.
Jan. 16 – IAEA Director General Amano released a statement confirming that Iran had removed excess centrifuges and equipment from the Fordow Fuel Enrichment Plant as required under the JCPOA.
Jan. 28 – Iran's nuclear agency, the Atomic Energy Organization of Iran (AEOI), announced that it had injected uranium hexafluoride (UF6) into its most advanced centrifuge model, the IR-8, as part of research and development efforts. Under the JCPOA, Iran was allowed to test centrifuges with UF6 gas so long as the process does would not produce an accumulation of enriched uranium.
Feb. 24 – IAEA Director General Yukiya Amano released the IAEA’s quarterly verification report determining Iran had thus far been compliant in implementing its nuclear-related commitments under the JCPOA. The report noted Iran was voluntarily implementing the Additional Protocol, pending formalization, and had enriched 101.7 kg of uranium to 3.67 percent U-235.
May 17 – The Trump Administration certified Iranian compliance with the JCPOA and continued to waive nuclear-related sanctions. The administration, however, simultaneously announced new sanctions on Iran’s ballistic missile program.
June 2 – IAEA Director General Amano released the IAEA’s quarterly verification report, which found Iran to be in compliance with the JCPOA. The report noted Iran was voluntarily implementing the Additional Protocol, pending formalization.
June 20 – U.N. Secretary General Antonio Guterres released his biannual report to the U.N. Security Council on the implementation of Resolution 2231 (2015). The report confirmed Iranian compliance with the JCPOA, but raised concerns about the travel of sanctioned individuals, called on Iran to cease ballistic missile testing following the January launch of the Khorramshahr, and affirmed reports that weapons seized by France in the Indian Ocean were of Iranian origin.
July 17 – The Trump administration certified Iranian compliance with its JCPOA obligations. The administration simultaneously announced new sanctions targeting Iran’s ballistic missile program and other policies.
Aug. 31 – IAEA Director General Amano released the IAEA’s quarterly verification report, which found Iran to be in compliance with the JCPOA. The report noted Iran was voluntarily implementing the Additional Protocol, pending formalization.
Oct. 13 – President Trump decertified Iranian compliance with the nuclear agreement and outlined a new policy for countering the Islamic Republic. “I am directing my administration to work closely with Congress and our allies to address the deal’s many serious flaws so that the Iranian regime can never threaten the world with nuclear weapons,” he said. Trump authored the Treasury Department to further sanction the Islamic Revolutionary Guard Corps. He stopped short, however, of reimposing sanctions lifted as part of the JCPOA. The move created an opportunity for Congress to reintroduce sanctions, should it see fit.
Nov. 13 – IAEA Director General Amano released his verification report, which acknowledged Iranian compliance with the JCPOA. The report noted Iran was voluntarily implementing the Additional Protocol, pending formalization.
Dec. 8 – U.N. Secretary General Guterres released his biannual report to the U.N. Security Council on the implementation of UNSC Resolution 2231 (2015). The report confirmed Iranian compliance with the JCPOA but raised concern about U.S. participation following Trump’s October 13 decision to not recertify the deal. The report also raised concerns about suspected Iranian arms transfers, ballistic missile activities, and the travel of sanctioned individuals, in violation of Resolution 2231.
Feb. 22 – IAEA Director General Amano released his verification report, which found that Iran had been complying with the JCPOA. The report noted Iran was voluntarily implementing the Additional Protocol, pending formalization. The report also said that Iran informed the IAEA of its intention to develop naval nuclear propulsion. The IAEA requested that Iran modify its Safeguards Agreement to provide the IAEA with preliminary facility designs. Iran had not replied to the request at the time of the report’s publishing.
April 30 – Israeli Prime Minister Netanyahu announced that Israel obtained some 100,000 “secret files that prove” Iran lied about never having a nuclear weapons program. Furthermore, he alleged that Tehran worked to “expand its nuclear weapons know-how for future use,” even after 2015 nuclear accord. Netanyahu presented maps, charts, photographs, and videos allegedly detailing Project Amad, whose goal was to design, produce and test nuclear weapons. The existence of Iran’s covert nuclear weapons program had been public knowledge for more than a decade.
May 8 – President Trump withdrew the United States from the JCPOA. The United States and European allies were unable to come to a compromise that would allay the administration’s concerns. “The fact is this was a horrible, one-sided deal that should have never, ever been made. It didn’t bring calm, it didn’t bring peace, and it never will,” Trump said in his address. Trump also announced his intention to reimpose sanctions on Iran that were lifted or suspended under the JCPOA. The United States gave businesses three to six months to comply with U.S. sanctions or face penalties.
May 18 – In an effort to salvage the JCPOA, the European Commission announced four measures in response to the reimposition of U.S. sanctions on Iran. They included launching a process to activate the Blocking Statute, which forbids E.U. persons from complying with U.S. extraterritorial sanctions, allows companies to recover damages incurred by sanctions from the sanctioning party, and nullifies foreign court judgments in the European Union.
May 23 – Supreme Leader Ayatollah Ali Khamenei issued six conditions that must be met by Europe for Iran to remain in the nuclear deal. He demanded that Europe secure “a resolution against the U.S. violation” of U.N. Security Council Resolution 2231, which endorsed the Joint Comprehensive Plan of Action (JCPOA). Khamenei said Europe must promise to stop objecting to its missile testing and actions in the Middle East as well as to stand against U.S. sanctions. He also sought protection for oil sales and financial transactions with Iran. "If the Europeans linger over our demands, Iran has the right to resume its nuclear activities. When we see that the JCPOA was useless, one way forward is to restart those halted activities," Khamenei warned in an address to government officials.
May 25 – Representatives of the remaining parties to the JCPOA met with Iranian representatives for the first time after the U.S. withdrawal. They discussed ways to continue with the deal without the United States.
June 5 – Supreme Leader Khamenei ordered the AEOI to prepare for increased uranium enrichment if the JCPOA were to collapse. AEOI director Ali Akbar Salehi announced plans to increase production of uranium hexafluoride (UF6), the input for centrifuges producing enriched uranium. He also said that Iran would install a new generation of advanced centrifuges at Natanz if the JCPOA failed. On June 13, an AEOI spokesman added that Iran would also resume uranium enrichment at Fordow if withdrew from the JCPOA. The AEOI emphasized that it was still abiding by the JCPOA’s terms.
July 5 – Foreign ministers from the remaining signatories to the JCPOA met with Iranian Foreign Minister Zarif in Vienna to discuss ways to blunt the impact of U.S. sanctions on Iran. It was the first time the ministers had met since President Donald Trump pulled the United States out of the JCPOA on May 8. They failed to reach consensus on the content or timing of economic support to Iran.
Aug. 6 – The United States reimposed sanctions banning transactions with Iran in U.S. dollars. It also sanctioned trade in precious metals, aluminum, steel, aircraft, coal, carpets, and food. The European Union enacted a “blocking statute” to protect European firms engaged in business with Iran from U.S. legal action.
Aug. 30 – The IAEA released its quarterly report verifying that Iran remained in compliance with the JCPOA.
Sept. 25 – The remaining signatories of the JCPOA pledged to create a “Special Purpose Vehicle” (SPV) that would enable firms to make payments to Iran. The SPV would bypass U.S. sanctions by not using U.S. dollars.
Sept. 27 – In a speech to the United Nations, Israeli Prime Minister Benjamin Netanyahu said that Iran had concealed a warehouse for nuclear material located near Tehran. Iran denied the allegation.
Nov. 5 – U.S. sanctions prohibiting the purchase of Iranian oil went into effect. The United States granted waivers to eight countries—China, Greece, India, Italy, Japan, South Korea, Taiwan, and Turkey—allowing them to continue importing Iranian oil at reduced rates. On November 12, the IAEA quarterly report reaffirmed Iran’s compliance with the JCPOA.
Dec. 12 – Secretary of State Mike Pompeo demanded that the United Nations update Resolution 2231 to ban Iran from developing nuclear-capable ballistic missiles. The resolution only “called upon” Iran to refrain from missile work.
Jan. 13 – AEOI director Ali Akbar Salehi said that Iran was designing a modern process that would allow it to enrich uranium faster if Tehran left the JCPOA.
Jan. 29 – Director of National Intelligence Dan Coats told the Senate Intelligence Committee, “We do not believe Iran is currently undertaking activities we judge necessary to produce a nuclear device.” President Donald Trump tweeted in response, “The Intelligence people seem to be extremely passive and naive when it comes to the dangers of Iran. They are wrong!”
February 14 – Vice President Mike Pence demanded that the United States’ European allies leave the JCPOA. "The time has come for our European partners to withdraw from the Iran nuclear deal and join with us as we bring the economic and diplomatic pressure necessary to give the Iranian people, the region and the world, the peace, security and freedom they deserve," Pence said at an Iran-focused summit in Warsaw. German Chancellor Angela Merkel rejected the demand. On February 22, the IAEA’s quarterly report reaffirmed Iran’s compliance with the JCPOA.
March 22 – The United States sanctioned several individuals and entities involved in Iran’s past nuclear weapons program. A U.S. intelligence assessment had concluded that Iran’s nuclear weapons work stopped in 2003, but Trump Administration officials claimed that Tehran had kept its nuclear weapons team together in case Iran’s leaders decided to resume work.
April 22 – Secretary of State Pompeo announced that the United States would stop providing sanctions exemptions to eight countries that imported Iranian oil: India, China, Turkey, Italy, Greece, South Korea, Taiwan, and Japan. “We will continue to apply maximum pressure on the Iranian regime until its leaders change their destructive behavior, respect the rights of the Iranian people, and return to the negotiating table,” said Pompeo. He noted that oil sales accounted for up to 40 percent of Iran’s revenue. The Trump administration's stated goal was to bring Iranian exports down to zero.
May 3 – The United States sanctioned imports of enriched uranium from Iran. JCPOA signatory countries—notably Russia—had imported Iran’s enriched uranium to prevent Tehran’s supply from exceeding the JCPOA’s cap. The U.S. sanctions made it difficult for Iran to remain within JCPOA limits without halting its enrichment. The United States extended sanctions waivers that allowed foreign firms to work on reconfiguring Iranian reactors for civilian use and that allowed countries to provide enriched uranium fuel for civilian reactors in Bushehr and Tehran.
May 8 – President Rouhani announced that Iran would stop complying with parts of the 2015 nuclear deal. In a televised speech to his cabinet, Rouhani said Iran would resume stockpiling excess uranium and heavy water used in its nuclear reactors. Rouhani warned that Iran would remove caps on uranium enrichment and resume work at the Arak nuclear facility if Iran’s oil and banking sectors are not protected from U.S. sanctions within 60 days. Rouhani expressed his impatience with the remaining parties to the JCPOA – Britain, China, France, Germany, and Russia. “We have given deadlines to JCPOA member states several times,” he said. "In simpler language, we felt that there was a need for surgery and the one-year-old painkillers were not enough; today's action is a surgical procedure to save the JCPOA, not to end it.”
In a statement, Iran’s Supreme National Security Council criticized the international community for not meaningfully responding to U.S. efforts to undermine the JCPOA, enshrined in U.N. Security Council Resolution 2231. “Unfortunately, the goodwill and wise self-restraint of the Iranian people have remained unanswered, and no operational mechanisms have been set up to compensate for U.S. sanctions except for the issuance of political statements.”
In a joint statement, the E.U. foreign policy chief and the foreign ministers of France, Germany and the United Kingdom reiterated their support for the JCPOA but also urged Iran to “implement its commitments under the JCPoA in full as it has done until now and to refrain from any escalatory steps.”
May 27 – President Trump offered to negotiate a new nuclear deal with Iran and identified nuclear weapons as his priority. “It [Iran] has a chance to be a great country with the same leadership,” Trump said. “We aren’t looking for regime change - I just want to make that clear. We are looking for no nuclear weapons.”
June 11 – U.S. Ambassador Jackie Wolcott claimed that Iran was in breach of the JCPOA after a U.N. nuclear watchdog report found that it had installed 33 advanced centrifuges. The agreement allows Iran to test 30. “The United States calls on Iran to return to compliance without delay. We understand the JCPOA Joint Commission is treating this issue with the seriousness it deserves, and we urge the JCPOA participants to address this issue as soon as possible,” she told the governing board of the International Atomic Energy Agency. But Wolcott also said Washington was open to talks with Tehran toward reaching a more comprehensive agreement.
July 1 – Iran breached the terms of the 2015 nuclear deal by exceeding limits on its stockpile of low-enriched uranium. Tehran is only allowed to store 300 kilograms of low-enriched uranium under the deal, negotiated by six major world powers. It is supposed to sell or exchange any surplus. "We told the Europeans that if more practical, mature and complete measures were taken, Iran's reduction (to its) commitments could be reversed. Otherwise, we will continue," said Foreign Ministry Spokesman Abbas Mousavi.
July 7 – Iran announced that it would begin enriching uranium past the 3.67 percent limit set by the 2015 nuclear deal. “Within hours, the technical tasks will be done and enrichment above 3.67 percent will begin. We predict that the IAEA measurements early tomorrow morning will show that we have gone beyond 3.67 percent,” said Iran nuclear agency spokesman Behrouz Kamalvandi. President Rouhani had given European countries until July 7 to provide sanctions relief.
July 8 – Iran began enriching uranium past the 3.67 percent mark specified by the 2015 nuclear agreement. The Atomic Energy Organization of Iran announced that it was enriching uranium at 4.5 percent. The IAEA confirmed the breach after an inspection. Foreign Ministry spokesman Abbas Mousavi warned that Iran’s next step will be “harder, more steadfast and somehow stunning” if European countries do not find a way to bypass U.S. sanctions.
July 10 – The United Sates accused Iran of committing “nuclear extortion” during an emergency meeting of the IAEA in Vienna. “There is no credible reason for Iran to expand its nuclear program, and there is no way to read this as anything other than a crude and transparent attempt to extort payments from the international community,” said U.S. Ambassador to the International Organizations in Vienna. President Trump vowed that the United States would respond with additional sanctions against Tehran.
July 14 – President Hassan Rouhani said Iran was ready to hold discussions with the United States if the Trump administration agreed to end crippling sanctions and return to the 2015 nuclear deal. “We have always believed in talks ... if they lift sanctions, end the imposed economic pressure and return to the deal, we are ready to hold talks with America today, right now and anywhere,” said Rouhani on state television.
July 18 – Iranian Foreign Minister Mohammad Javad Zarif offered to immediately accept more intrusive international inspections of Tehran’s nuclear facilities if the United States agreed to lift sanctions. He told a group of reporters that Iran’s parliament would fast track the Additional Protocol of the IAEA that would allow extensive monitoring of its nuclear program. “If Trump wants more for more, we can ratify the Additional Protocol and he can lift the sanctions he set,” Zarif said. "He has said that he will take any measure to Congress – fine. Lift the sanctions and you’ll have the Additional Protocol sooner than 2023.” The 2015 nuclear deal originally required Iran's parliament to ratify the clause by October 2023.
July 28 – The remaining signatories of the JCPOA—Britain, France, Germany, Russia, China, and Iran—met in Vienna to salvage the 2015 nuclear deal. "The atmosphere was constructive. Discussions were good. I cannot say that we resolved everything, I can say there are lots of commitments," said Iranian Deputy Foreign Minister Seyed Abbas Araghchi.
Fu Cong, the representative of the Chinese delegation, said that all parties “strongly opposed” the U.S. decision to leave the deal and impose unilateral sanctions on Tehran. The Europeans urged Iran to fully comply with the nuclear deal, and all parties agreed to hold a higher-level meeting with foreign ministers in the future. No date was announced at the summit.
Ali Akbar Salehi, the head of Iran’s Atomic Energy Organization, announced Tehran would restart activities at the Arak heavy water nuclear reactor. Salehi added that Iran had enriched 24,000 kilograms of uranium since 2015. The nuclear deal restricted Iran to a 300-kilogram stockpile.
July 31 – Foreign Minister Mohammad Javad Zarif warned that Iran would “take the next step” in cutting commitments to the JCPOA if Europe failed to shield Tehran from U.S. sanctions. Zarif added that European countries should guarantee the sale of Iranian oil.
The U.S. State Department renewed five sanctions waivers permitting foreign firms to work on Iran’s civil nuclear program without penalties. The waivers, which were renewed for an additional 90 days, specifically permitted European, Russian, and Chinese companies to continue civil nuclear projects at Iranian nuclear facilities.
Aug. 12 – Foreign Minister Zarif reaffirmed Iran’s commitment to the 2015 nuclear deal. “It wasn't the best deal for everybody because you cannot have the perfect deal. There is no perfect deal," he said. "And if President Trump is given correct advice, he will be able to basically accept the reality that this is the best deal possible and we can move forward."
Aug. 19 – Ali Shamkhani, the secretary of Iran’s Supreme National Security Council, said it was a mistake for Iran to sign the 2015 nuclear deal. He added that the U.S. “maximum pressure” campaign would not force concessions from Tehran. "The sanctions campaign is not for negotiation, it's for making us surrender," said Shamkhani. "As long as this approach is taken by the United States, Iran will never ever seek negotiations."
Aug. 22 – Iran said it was ready to negotiate with France over proposals to salvage the 2015 nuclear deal. French President Emmanuel Macron said Paris was willing to reduce sanctions or develop a compensation mechanism if Iran agreed to return to the deal. “There are proposals on the table, both from the French and the Iranian side, and we are going to work on those proposals tomorrow,” said Iranian Foreign Minister Mohammad Javad Zarif.
Aug. 30 – An IAEA report revealed that Iran had again breached the 2015 nuclear deal by increasing its stock of enriched uranium and refining it to a greater purity. The assessment said Iran had accumulated 241.6 kg of enriched uranium and was enriching at up to 4.5 percent, up from 202.8-kg at 3.67 percent in an IAEA report from July.
Sept. 2 – Iran threatened to further reduce its commitments to the 2015 nuclear deal by Sept. 6 if the European Union did not find a way to ease U.S. sanctions. Tehran said it would take measures such as resuming uranium enrichment at 20 percent, which it said it could do within one to two days. “The third step has been designed and will be stronger than the first and second steps to create balance between Iran’s rights and commitments to the JCPOA,” said foreign ministry’s spokesman Abbas Mousavi.
Sept. 4 – Iranian President Hassan Rouhani announced that Tehran would give Europe another two months to salvage the 2015 nuclear deal before it took further steps to reduce its commitments. Iran originally set the deadline as Sept. 6.
Rouhani said Iran would begin developing centrifuges for faster uranium enrichment at nuclear power plants. “From Friday, we will witness research and development on different kinds of centrifuges and new centrifuges and also whatever is needed for enriching uranium in an accelerated way,” Rouhani said. “All limitations on our Research and Development will be lifted on Friday.”
Sept. 7 – Iran announced that it had begun using an array of 20 IR-6 centrifuges and an array of 20 IR-4 centrifuges to enrich uranium. The IR-6 and IR-4 centrifuges are 10 and five times, respectively, as fast as the IR-1s. Under the JCPOA, Iran was only allowed to use 5,060 IR-1s.
Sept. 8 – Two diplomatic sources told Reuters that the IAEA found uranium traces at a site that Israeli Prime Minister Netanyahu alleged was a “secret atomic warehouse.” The uranium was not highly enriched but called Tehran’s transparency into question. U.S. National Security Advisor John Bolton demanded a report as soon as possible.
Sept. 9 – Prime Minister Netanyahu alleged that Iran conducted experiments relating to nuclear weapons development at a site near the city of Abadeh. “When Iran realized that we uncovered the site, here’s what they did,” he said in televised remarks, showing a photograph of the site from a month later. “They destroyed the site. They just wiped it out.”
On Twitter, Foreign Minister Zarif accused Netanyahu of lying and posted a picture of a newspaper story discussing Israel’s undeclared nuclear arsenal in Dimona.
Sept. 25 – The IAEA found that Iran had breached the JCPOA again by using advanced centrifuges to enrich uranium. The U.N. watchdog “verified that all of the (centrifuge) cascades already installed in R&D lines 2 and 3 ... were accumulating, or had been prepared to accumulate, enriched uranium,” according to a new report. The JCPOA only allowed Iran to use some 5,000 of its first-generation IR-1 centrifuges to enrich uranium. Advanced centrifuges were supposed to only be used in small numbers for research purposes.
Nov. 4 – Iran began operating 30 new IR-6 centrifuges, doubling its number of the advanced machines. The chief of the Atomic Energy Organization of Iran, Ali Akbar Salehi, said Iran was operating 60 of the centrifuges, which are some 10 times more efficient than the IR-1s allowed under the JCPOA. The announcement coincided with the 40th anniversary of the takeover of the U.S. embassy in Tehran by students.
Salehi said that Iran went from producing about 450 grams (1 pound) of low-enriched uranium a day to 5 kilograms (11 pounds). He said Iran’s stockpile had grown beyond 500 kilograms (1,102 pounds). The JCPOA had limited Iran’s stockpile to 300 kilograms (661 pounds)
Nov. 5 – President Hassan Rouhani announced that Iran will start injecting gas into 1,044 centrifuges at Fordo in one day. The heavily fortified facility, built inside a mountain, was intended to be a research facility under the JCPOA, not an active site. The IR-1 centrifuges at Fordo had been spinning but were not enriching uranium. Ali Akbar Salehi, the head of the Atomic Energy Organization of Iran, said Iran would begin enriching uranium to five percent at Fordo.
On November 6, Kamalvandi clarified that uranium gas would only be injected into 696 of the centrifuges and that the remaining 348 would produce stable medical isotopes.
Nov. 6 – Iran reportedly held International Atomic Energy Agency (IAEA) inspector and confiscated her travel documents while she was at the Natanz nuclear facility. The 2015 nuclear deal allowed for periodic IAEA inspections to ensure Iran was adhering to regulations. The IAEA’s Board of Governors convened an emergency meeting on November 7 to discuss the matters.
Nov. 7 – Iran injected uranium gas into the centrifuges at Fordo. Secretary of State Pompeo accused Tehran of extorting the international community into accepting its nuclear program and behavior in the region.
Nov. 11 – In its quarterly report, the U.N. nuclear watchdog said that Iran had violated the 2015 nuclear deal by increasing its stockpile of enriched uranium. The IAEA also reported that its inspectors had found traces of uranium “at a location in Iran not declared to the agency.”
France, Germany, Britain, and the European Union issued a joint statement saying they were “extremely concerned” by Iran’s latest moves. “Iran’s action is inconsistent with the JCPOA’s clear provisions on Fordow and has potentially severe proliferation implications,” the statement said. “We affirm our readiness to consider all mechanisms in the JCPOA, including the dispute resolution mechanism, to resolve the issues related to Iran’s implementation of its JCPOA commitments.”
Nov. 12 - Iranian Foreign Minister Mohammad Javad Zarif criticized the European Union’s warning to Tehran over advancements of its nuclear program and accused the Europeans of failing to fulfill their commitments to the 2015 nuclear deal.
Nov. 16 – Iran informed the IAEA that its stock of heavy water exceeded the 130 metric ton limit under the JCPOA. On the following day, the watchdog confirmed that the Heavy Water Production Plant was active and that Iran had 131.5 metric tons of heavy water. Heavy water is often used as a moderator to slow down reactions in nuclear reactors.
Heavy water reactors can produce plutonium for use in nuclear weapons. But heavy water poses less of a proliferation concern than uranium because spent fuel from heavy water reactors must be reprocessed to separate the plutonium.
Nov. 18 – Secretary of State Mike Pompeo said the United States will cancel sanctions waivers for projects at Iran’s Fordow nuclear plant effective December 15. “The right amount of uranium enrichment for the world’s largest state sponsor of terror is zero ... There is no legitimate reason for Iran to resume enrichment at this previously clandestine site,” Pompeo said. The waivers had allowed foreign firms to work on Iran’s civil nuclear program without penalties.
Nov. 27 - French Foreign Minister Jean-Yves Le Drian warned that Paris would consider activating the dispute mechanism of the 2015 nuclear deal, which could eventually trigger U.N. sanctions against the Islamic Republic. “Every two months, there is another dent (in the deal by Iran) to the point where today we ask ourselves, and I’m saying this very clearly, about the implementation of the dispute resolution mechanism that exists in the deal,” he said.
Dec. 2 - Rafael Mariano Grossi, the incoming chief of the U.N. nuclear watchdog, said that he would take a “firm and fair” approach to Iran’s nuclear program. “An inspector is not a friend. He’s someone who comes and needs to ascertain the facts without bias, without agenda, in an objective and impartial way,” Grossi said. “This has to be done in firmness, but in fairness as well.”
Dec. 3 - Rafael Mariano Grossi, the incoming chief of the U.N. nuclear watchdog, said the agency was still awaiting an explanation from Tehran after detecting uranium at an undeclared site. Israel and the United States had urged the International Atomic Energy Agency to investigate a “secret atomic warehouse,” which Israeli Prime Minister Benjamin Netanyahu revealed during his 2018 U.N. address. “The process continues,” Grossi said. “We have so far not received an entirely satisfactory reply from them, but the exchanges continue.”
Dec. 4 - President Rouhani said that Iran was still open to nuclear negotiations with the United States. He stipulated that Washington must first remove all sanctions imposed on the Islamic Republic. “If America lifts the sanctions, we are ready to talk and negotiate, even at the level of heads of the 5+1 countries (major powers that were party to the 2015 nuclear deal),” Rouhani said.
Dec. 6 - European countries condemned Iran’s violations of the 2015 nuclear deal but said the JCPOA was “still alive.” During the nuclear discussions, Tehran told European powers that it would continue to breach the deal until it served Iran’s interests. Iran had breached the JCPOA at least four times since July.
Dec. 19 - President Rouhani said that Iran would begin to test a new type of advanced centrifuge. Use of advanced centrifuges to enrich uranium would be a violation of the 2015 nuclear deal. Tehran had already breached the agreement five times since July 1. “We have had great achievements and today, Iranian new IR-6 centrifuges are working and models IR-9 are currently being tested.”
Dec. 20 - Britain, France and Germany were considering to trigger a dispute mechanism clause of the 2015 nuclear deal to put further pressure on Iran to abide by the agreement, according to diplomats. But the European powers would not rush to reimpose U.N. sanctions on Iran, which would reduce any chance to salvage the deal.
Jan. 5 - Iran announced that it would no longer abide by restrictions on uranium enrichment imposed by the 2015 nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA). “The Islamic Republic of Iran, in the fifth step in reducing its commitments, discards the last key component of its operational limitations in the JCPOA, which is the limit on the number of centrifuges,” the government said. Tehran emphasized that all its actions were reversible and that it would return to the deal if sanctions would be lifted and its interests could be guaranteed. Iran said it would continue to cooperate with International Atomic Energy Agency inspectors.
Jan. 8 - Trump called on the remaining parties to the 2015 nuclear deal – Britain, China, France, Germany, and Russia – to withdraw from the agreement and work toward a new, more comprehensive one. “We must all work together toward making a deal with Iran that makes the world a safer and more peaceful place,” he added. “The civilized world must send a clear and unified message to the Iranian regime: Your campaign of terror, murder, mayhem will not be tolerated any longer.”
Jan. 14 - Britain, France and Germany triggered the dispute resolution mechanism under the 2015 nuclear deal. It was the strongest action taken by European powers to enforce the agreement. If Iran does not return to compliance, the process could result in the reimposition of U.N. sanctions and ensure that an arms embargo does not expire in October 2020. The parties will have some 60 days to negotiate.
Jan. 15 - President Rouhani responded defiantly to Britain, France and Germany’s decision to trigger the nuclear deal’s dispute resolution mechanism. "In recent days I... made it clear to two European leaders that what we have done is reversible for one, and that everything we do regarding the nuclear issue is under the supervision of the IAEA,” Rouhani said. “If you take the wrong step, it will be to your detriment. Pick the right path. The right path is to return to the nuclear deal.
Jan. 16 - President Rouhani announced that Iran had begun enriching more uranium than before the 2015 nuclear deal. He did not detail how much more uranium was being enriched. Rouhani added that the country’s nuclear program was better off today than before the deal.
Jan. 25 - Ali Asghar Zarean, an aide to Iran’s nuclear chief, said the country had accumulated 1,200 kilograms of low-enriched uranium, far more than the 202.8-kilogram limit under the JCPOA. The announcement suggested Tehran had significantly ramped up enrichment since November, when the IAEA said the stockpile was 372.3 kilograms.
Feb. 3 - Iranian President Hassan Rouhani said that Tehran would bar U.N. inspectors from nuclear facilities if the country were faced with “a new situation.” The warning came during a visit with the Josep Borrell, the new E.U. foreign affairs chief.
Rouhani added that Iran was willing to negotiate with European powers. “The Islamic Republic of Iran is still ready for interaction and cooperation with the European Union for resolving issues and, whenever the opposite side completely upholds their commitments, Iran will return to its commitments,” he said.
Feb. 4 - The European Union said that it would avoid sending a dispute over the 2015 nuclear deal to the U.N. Security Council. “We are in agreement not to go directly to a strict time limit which would oblige (us) to go to the Security Council,” said E.U. foreign affairs chief Josep Borrell during a two-day trip to Tehran. After Britain, France and Germany triggered the deal’s dispute mechanism, the parties technically had a 15-day period to resolve issues with Iran.
March 3 - The IAEA released two reports that criticized Iran for violations of the JCPOA. Iran had tripled its stockpile of low- enriched uranium over the previous three months, it said in one report. It shortened the breakout time to produce enough fissile material for a nuclear weapon, although the IAEA did not find evidence that Iran had taken steps to produce a bomb. In the second report, the IAEA condemned Iran’s refusal to grant inspectors access to three sites of interest. The report said that it found evidence from early July 2019 that was consistent with efforts to “sanitize” part of an unnamed location to obscure nuclear material.
June 19 - The world’s nuclear watchdog passed a resolution—25 to two, with seven abstentions—calling on Iran to fully cooperate with an investigation into its past nuclear work after more than a year of stonewalling. Iran had denied inspectors access to two suspect sites where it was suspected of storing undeclared nuclear material The resolution was the first formal challenge of Iran in eight years from the IAEA Board of Governors.
July 2 - A mysterious explosion extensively damaged Iran’s main nuclear enrichment site at Natanz. The blast damaged a factory producing advanced IR-4 and IR-6 centrifuges that enrich uranium faster than the IR-1 models allowed under the 2015 nuclear deal. Enriched uranium can be used to produce energy or fuel a bomb. The damage set back the enrichment program by months, Iran conceded.
Oct. 28 - The IAEA reported that Iran was building a new underground centrifuge assembly plant at the Natanz facility after the previous plant was damaged in an explosion in July.
Nov. 2 - The world’s nuclear watchdog agency reported that Iran had amassed 12 times the enriched uranium permitted by the 2015 nuclear deal. The JCPOA stipulated that Tehran was limited to producing a maximum of 203 kilograms (or 447 pounds) of uranium enriched to only 3.6 percent. Tehran had stockpiled 2,443 kilograms (or 5,386 pounds) of uranium enriched to 4.5 percent, the IAEA reported.
Experts claim that Iran could produce two nuclear weapons if it enriched its entire stockpile to 90 percent. Because of its growing stockpile, the so-called breakout time needed to enrich enough uranium for one nuclear bomb decreased from more than a year to about three months, the Institute for Science and International Security estimated. Generating fuel is one of three steps required to make a viable bomb; the others are designing the weapon and marrying it to a delivery system, such as a missile or a bomb from a warplane.
Nov. 18 - The IAEA and the United States urged Iran to provide more information about uranium particles found nearly two years earlier at Turqazabad, a possible site not declared to international inspectors. “What they are telling us from a technical point of view doesn’t add up, so they need to clarify this,” IAEA Director General Rafael Grossi told reporters. Iran had claimed that the warehouse was a carpet-cleaning facility after Israel had revealed its existence in September 2018.
Nov. 27 - Mohsen Fakhrizadeh, widely believed to be the pioneer behind Iran’s nuclear weapons program, was assassinated in a roadside attack about 40 miles east of Tehran. Iran blamed Israel and vowed retaliation. Supreme Leader Ayatollah Ali Khamenei ruled out new diplomacy with the United States in a statement read by his representative at the scientist’s funeral on November 30.
Dec. 1 - Iran’s parliament, which is dominated by conservatives and hardliners, passed a bill requiring the government to immediately resume enriching uranium to 20 percent and to stockpile 120 kilograms (265 pounds) of it annually. Uranium must be enriched to 90 percent or above to fuel a weapon. Parliament also called on President Rouhani, who opposed the bill, to restrict IAEA inspectors if U.S. sanctions—on Iran's banking and oil sectors—were not lifted within a month. The Guardian Council later extended the deadline to two months.
Jan. 4 - The IAEA confirmed that Iran had begun enriching uranium up to 20 percent at Fordo. The agency verified that centrifuges cascades at Fordo had been reconfigured to enrich levels of uranium from 4.1 percent to 20 percent.
Feb. 2 - The IAEA confirmed that Iran had completed installation of 174 more IR-2M centrifuges at Natanz and began feeding uranium gas into them. In total, Iran was enriching uranium with 5060 IR-1 centrifuges and 348 IR-2M centrifuges at Natanz.
Feb. 10 - The IAEA confirmed that Iran had enriched 3.6 grams of natural uranium metal. Iran would need 500 grams of highly enriched uranium metal for a nuclear weapon core.
Feb. 15 - Iran threatened to block IAEA snap inspections if the U.S. did not lift sanctions by February 21. The government said that did not plan to end all inspections, just those mandated under the Additional Protocol. "All these steps are reversible if the other party changes its path and honors its obligations,” Foreign Ministry spokesman Saeed Khatibzadeh said.
Feb. 17 - Iran informed the IAEA that it would install two new cascades of advanced centrifuges at Natanz. Each cascade had 174 IR-2M centrifuges and would enrich uranium up to 5 percent.
Feb. 19 - The IAEA detected uranium particles at two sites that may have been used for the storage and testing of undeclared nuclear materials in the early 2000s. Iran had previously blocked access to the sites for seven months before granting the IAEA access in August 2020, which called its commitment to transparency into question. Tehran had a secret nuclear weapons program until 2003, when it was disbanded, according to U.S. intelligence.
Feb. 21 - The IAEA and Iran agreed on an compromise that would provide the nuclear watchdog less access to the country's declared and undeclared nuclear sites. Under the arrangement, the nuclear watchdog could not access cameras installed at declared nuclear sites but Iran will be required to save all surveillance footage for three months. If the United States lifts sanctions on Iran, Tehran will hand over the tapes to the IAEA. If the Biden administration does not lift punitive economic measures, the footage “will be deleted forever," the Atomic Energy Organization of Iran said. IAEA director general Raphael Grossi called it a “temporary solution” that “salvages the situation.”
Feb. 23 - Iran suspended compliance with the Additional Protocol, a voluntary agreement that grants inspectors “snap” inspections and was part of the 2015 nuclear deal negotiated with the world’s six major powers. But Foreign Minister Mohammad Javad Zarif said that the step, and all other breaches of the deal, was "reversible" if the Biden administration lifted sanctions.
Mar. 1 - Iran had failed to provide a "necessary, full and technically credible explanation" for the presence of uranium particles at undeclared sites," IAEA chief Raphael Grossi told the Board of Governors. "The Agency is deeply concerned that undeclared nuclear material may have been present at this undeclared location and that such nuclear material remains unreported by Iran under its Safeguards Agreement," he said.
Mar. 8 - The IAEA confirmed that Iran had begun feeding uranium gas into a third cascade of advanced centrifuges at Natanz, Reuters reported. A fourth cascade of IR-2M centrifuges was installed but not enriching uranium, while installation of a fifth cascade was ongoing. Each cascade had 174 IR-2M centrifuges.
Mar. 15 - The IAEA confirmed that Iran had begun enriching uranium at Natanz with IR-4 centrifuges. The IR-4 was the second type of advanced centrifuge, after the IR-2M, operating at the Natanz facility.
April 1 - The IAEA confirmed that Iran had begun enriching uranium with a fourth cascade of 174 IR-2M centrifuges. Iran was now using a total of 696 IR-2M centrifuges at Natanz.
April 7 - Iran and the IAEA delayed talks in Tehran originally scheduled for early April. Rafael Grossi, director general of the International Atomic Energy Agency, told Newsweek that the agency planned to ask Iran questions about uranium participles discovered at undeclared sites.
April 8 - Deputy Foreign Minister Abbas Araghchi met with IAEA Director General Grossi while in Vienna. Araghchi said that the IAEA would play an "important role" in verification if Iran came to an agreement with the world powers over returning to compliance with the JCPOA. He added that Iran would engage with the IAEA "in good faith" about outstanding nuclear issues, such as the discovery of uranium particles at undeclared sites. "I am confident we are able to resolve those questions as soon as possible," he told Press TV.
April 10 - Iran began testing its most advanced nuclear centrifuge, the IR-9, at the Natanz enrichment site. Under the nuclear deal, Iran could only operate 5,060 first-generation IR-1 centrifuges until 2025. The IR-9 can enrich uranium 50 times faster than the IR-1.
April 11 - An explosion at Natanz hit the power supply for centrifuges and caused damage that could take up to nine months to fully repair, The New York Times reported. It was the second major attack to sabotage operations at Natanz in less than a year. In July 2020, an explosion caused significant damage to a centrifuge factory. Foreign Minister Zarif blamed Israel and vowed revenge. “We will not fall into their trap,” he told a state television. “We will not allow this act of sabotage to affect the nuclear talks.”
April 13 - Iran said that it would begin enriching uranium to 60 percent, the highest level of enrichment that it has publicly acknowledged. The move would be a major breach of the 2015 nuclear deal and brought Tehran closer to having weapons grade uranium. Iran also planned to install 1,000 additional centrifuges at Natanz.
April 14 - The breach coincided with the planned resumption of indirect talks between the United States and Iran in Vienna over returning to the JCPOA. The White House said that it was “concerned” about the “provocative” announcement. Britain, France and Germany said that the move was "dangerous" and "contrary to the constructive spirit and good faith of these discussions."
April 15 - Indirect talks over getting the United State and Iran back into compliance with the JCPOA resumed in Vienna. In Tehran, President Rouhani reiterated that Iran was not seeking a nuclear weapon. “We can enrich 90 percent today, but we stand by our word and we are not looking for an atomic bomb,” he said during a cabinet meeting. “It is YOU who made and stockpiled the atomic bomb and are still making bombs. This is what YOU do. Do not accuse us of making bombs, Iran's activities are completely peaceful.”
April 16 - Iran began enriching uranium up to 60 percent. “We are producing about nine grams of 60 percent enriched uranium an hour,” AEOI chief Salehi said.
Garrett Nada, Eli Pollock, Cameron Glenn, Daniel Schnur, John Caves, Alex Yacoubian and Andrew Hanna also contributed to this timeline.