- Iran is a charter member of the Nuclear Non-Proliferation Treaty (NPT), the guide for the global fight against the spread of atomic weapons. Iran insists its nuclear program is for energy, not a bomb.
- Iran cites the NPT to justify its nuclear work, including uranium enrichment, which can be used to generate electricity or to make a bomb. Article IV guarantees “the inalienable right of all the Parties to the Treaty to develop research, production and use of nuclear energy for peaceful purposes without discrimination.”
- Iran claims to honor the NPT obligations for monitoring its atomic program. It has been careful not to break the safeguards agreement that allows U.N. inspectors from the International Atomic Energy Agency (IAEA) to verify compliance with the NPT.
- The IAEA cited Iran for breach of safeguards, saying the Islamic Republic hid parts of its nuclear program and failed to answer questions on possible military work. This led the U.N. Security Council to impose sanctions in 2010 to get Iran to provide data and to suspend enrichment to allay fears it seeks nuclear weapons.
- The IAEA will play a critical role in monitoring the implementation of the final nuclear deal reached by Iran and the world’s six major powers on July 14, 2015.


- The IAEA was empowered to monitor all sites where there was nuclear material. But it clashed with Iran over access to sites where nuclear material had not yet been introduced, such as at a reactor being built in Arak that could eventually make plutonium.
- The IAEA was particularly frustrated about Iran blocking access to key Iranian scientists, including Mohsen Fakhrizadeh, who has allegedly led Iran’s atomic weapons work.
- The IAEA monitored Tehran’s compliance with U.N. Security Council resolutions.
- It also oversaw attempts to supply fuel to a research reactor in Tehran.
- February 24, 2004: The IAEA reports that Iran is working to develop a more powerful centrifuge and on separating Polonium-210, which can be used in weapons.
- March 13, 2004: The IAEA board reprimands Iran for hiding possible weapons-related activities.
- March 17, 2004: Testifying before the U.S. Congress, IAEA chief Mohamed ElBaradei says the “jury is still out” on Iran’s nuclear program.
- November 2004: In the Paris Agreement, European negotiators, the IAEA and Iran agree on the terms to suspend uranium enrichment.
- August 8, 2005: The IAEA reports that Iran had ended suspension and begun work to convert uranium into fuel for enrichment.
- September 2, 2005: The IAEA reports that there are still unresolved issues regarding Iran’s nuclear program and says that full Iranian cooperation is “overdue.”
- September 24, 2005: The IAEA board votes 22-1, with 12 abstentions, to find Iran in “non-compliance” with the NPT’s Safeguards Agreement. This clears the way to report Iran to the Security Council for action.
- February 4, 2006: After failing to win Iran’s cooperation, the IAEA board votes 27-3, with five abstentions, to refer Iran to the Security Council, pending one more report from ElBaradei
- February 27, 2006: ElBaradei reports that the IAEA is still uncertain about both the scope and nature of Iran’s nuclear program. The report is sent to the Security Council.
Case to the U.N.

- The Gchine mine in Bandar Abbas
- The Heavy Water Production Plant near Arak
- All new research reactors
- The identification of 16 sites designated for the construction of nuclear power plants
- Iran’s announcements about additional enrichment facilities
- Laser enrichment technology
Before the deal is implemented, the IAEA must confirm that Iran:
- Reduced its supply of excess heavy water and halted construction on the Arak reactor
- Reduced its capacity to 5,060 centrifuges, enrichment levels to 3.67 percent, and its uranium stockpile to 300 kg
- Ceased enrichment activity at Fordo
- Is conducting R&D within the parameters specified by the JCPOA
- Notified the IAEA that it has provisionally applied the Additional Protocol

- The IAEA was founded in 1957 as a direct result of the U.S. “Atoms for Peace” initiative to spread peaceful nuclear technology and stop the proliferation of atomic weapons. It has 165 member states.
- Iran had no centrifuges turning in 2003, when the IAEA investigation began. By August 2010, it had 3,772 centrifuges enriching uranium and 5,084 more installed but not yet enriching, according to an IAEA report.
- In August 2015, the IAEA reported that Iran had 16,428 centrifuges installed at Natanz and 2,710 installed at Fordo. The nuclear deal requires Iran to reduce its number of centrifuges to 6,104 -- 5,060 of which will be permitted to enrich uranium – for 10 ten years. The excess centrifuges will be placed under continuous IAEA monitoring.
- As of June 2015, 126 states had implemented the Additional Protocol. Iran was one of 20 states that had signed the protocol, but not brought it into force – the step required to make it legally binding for the state.
- Even under Mahmoud Ahmadinejad’s controversial presidency, Tehran wanted to maintain at least minimal cooperation with the International Atomic Energy Agency, since kicking out all inspectors could have led to a harsher international response, including more severe sanctions and even military strikes.
- The extent of international inspectors’ access to Iranian facilities – particularly military sites – was a key sticking point during the nuclear talks. If the deal is fully implemented, the IAEA will have greater access to information about Iran’s nuclear program for at least the next two decades.
- The Islamic Republic is likely to continue to insist its nuclear program is strictly for peaceful nuclear energy, even if other secret sites or work are uncovered.
IAEA Reports on Iran Nuclear Deal
The following are summaries of reports and updates by the International Atomic Energy Agency on Iran’s nuclear program since January 2016, when the nuclear deal went into its implementation phase.
Jan. 16, 2016: IAEA Director General Yukiya Amano confirmed that Iran had taken the necessary steps to start implementation of the nuclear deal, also known as the Joint Comprehensive Plan of Action (JCPOA). Inspectors on the ground verified that Tehran reduced its enriched uranium stockpile, cut and capped its capacity to enrich uranium, modified the Arak heavy water rector to block its ability to produce plutonium, and allowed more robust monitoring by the IAEA.
Feb. 26, 2016: The IAEA’s first quarterly report on Iran’s nuclear program following implementation noted that Iran briefly exceeded the 130 metric ton limit on its heavy-water stockpile. Tehran, however, reduced the 130.9 tons back below the limit by shipping out 20 metric tons. The report was short but detailed Iran’s compliance with specific aspects of the deal.
May 27, 2016: The IAEA report to the Board of Governors found that Iran was living up to its commitments under the nuclear deal. The watchdog said that Iran accepted additional inspectors and provided complementary access to sites and facilities under the Additional Protocol.
Sept. 8, 2016: The IAEA report to the Board of Governors found that Iran was living up to its commitments under the nuclear deal. For example, Iran had not surpassed limits on its stock of enriched uranium or heavy water. As with earlier quarterly reports, however, this one did not include details about every restriction in JCPOA.
Nov. 17, 2016: The IAEA report found that while Iran was in general compliance with its obligations, the country’s stocks of heavy water had exceeded the limit by 0.1 metric tons. Iran, however, informed the IAEA of its plan to ship it out of the country.
Jan. 19, 2017: IAEA Director General Amano and U.S. Energy Secretary Ernest Moniz confirmed that Iran had removed certain infrastructure and excess centrifuges from the Fordow Fuel Enrichment Plant by the one-year anniversary of implementation, as required under the nuclear deal.
Feb. 24, 2017: The Director General’s report found that Iran was complying with the JCPOA. The report said that Tehran was not continuing construction of its heavy water research reactor at Arak. Iran’s stockpile of low-enriched uranium —which can be used for peaceful purposes but could also be reprocessed for use in a weapon —was 101.7 kilograms, well below the 300-kilogram limit. Earlier in 2017, Iran had reportedly come close to reaching the limit before a large amount stuck in pipes was recategorized as unrecoverable.
May 9, 2018: Director General Amano said Iran “is subject to the world’s most robust nuclear verification regime under the JCPOA, which is a significant verification gain.” In a statement, he asserted that “the IAEA can confirm that the nuclear-related commitments are being implemented by Iran.”
June 2, 2017: The IAEA report’s findings indicated that Iran was complying with the JCPOA. Tehran’s stockpile of low-enriched uranium was 79.8 kilograms, less than in the previous report and well below the 300-kilogram limit. The report, however, did not include any details about how the IAEA was confirming that Iran was not undertaking certain activities related to weaponization.
Aug. 31, 2017: The IAEA reported that Iran was complying with the JCPOA. Director General Amano, however, rejected Tehran’s claim that its military sites were off-limits to inspectors. He told The Associated Press that his agency "has access to (all) locations without making distinctions between military and civilian locations" under the JCPOA.
Sept. 11, 2017: Amano reported to the IAEA Board of Governors that nuclear related commitments were being implemented. “The Agency continues to verify the non-diversion of nuclear material declared by Iran under its Safeguards Agreement. Evaluations regarding the absence of undeclared nuclear material and activities in Iran remain ongoing,” he said.
Nov. 13, 2017: The IAEA released its eighth verification report indicating Iranian compliance with the deal. Iran’s low-enriched uranium stockpile as of November 5 was 96.7 kg, more than what was reported previously but still well below the limit. Iran’s stock of heavy water was 114.4 metric tons, below the 130-ton limit.
Feb. 22, 2018: The IAEA released a quarterly report acknowledging Iran’s compliance with the JCPOA. It noted that Iran notified the watchdog of a “decision that has been taken to construct naval nuclear propulsion in future.” Iranian leaders have previously mentioned that goal, which would increase Iran’s naval power and could involve enriching uranium beyond the limits of the nuclear deal.
May 24, 2018: The IAEA released a quarterly report, the first since the United States withdrew from the nuclear deal, showing Iranian adherence to the JCPOA. The watchdog found that Iran’s stockpile of heavy water remained below the agreed limit of 130 tons during the previous three months. Iran had slightly exceeded that limit twice since the JCPOA went into effect. It noted that Tehran was implementing the Additional Protocol, which provides the watchdog with great access to nuclear sites. But the report also suggested that “proactive cooperation by Iran in providing such access would facilitate implementation of the Additional Protocol and enhance confidence.”
Aug. 30, 2018: The IAEA released a quarterly report indicating Iranian compliance with the nuclear deal. The watchdog was able to carry out all necessary inspections. “Timely and proactive cooperation by Iran in providing such access facilitates implementation of the Additional Protocol and enhances confidence,” said the report.
Sept. 10, 2018: In his introductory statement to the IAEA Board of Governors, Director General Amano said Iran was implementing its commitments under the JCPOA. “It is essential that Iran continues to fully implement those commitments,” he added.
Nov. 12, 2018: The IAEA’s quarterly report noted that Iran was complying with the JCPOA. The agency said it had access to all the necessary sites and that Iran’s heavy water and low-enriched uranium stockpiles remained within the limits.
Feb. 22, 2019: The IAEA again found that Iran was complying with the JCPOA. Much of the language matched that of the previous quarterly report. “Timely and proactive cooperation by Iran in providing such access facilitates implementation of the Additional Protocol and enhances confidence,” stated the IAEA. On March 4, Amano confirmed that Iran “is implementing its nuclear commitments.”
May 31, 2019: An IAEA safeguards report found that Iran was in compliance with the JCPOA. But it also noted that Tehran’s stockpiles of low-enriched uranium and heavy water were growing. It also raised questions about whether Iran potentially overstepped limits on advanced centrifuge installation. It had installed 33, more than the maximum of 30, according to one interpretation of the JCPOA. On June 10, Amano said “the [uranium] production rate is increasing,” but he did not provide further details. He added that he was “worried about increasing tensions over the Iranian nuclear issue.”
Aug. 30, 2019: An IAEA safeguards report confirmed that Iran had begun to enrich uranium to 4.5 percent, beyond the 3.67 percent limit stipulated in the JCPOA. The agency also verified that Iran’s stockpile of low-enriched uranium exceeded the 300 kg limit. Iran continued to adhere to other aspects of the deal and allowed inspectors access to all sites that they needed to visit. But the report implied that Iran’s cooperation could use improvement. “Ongoing interactions between the Agency and Iran...require full and timely cooperation by Iran. The Agency continues to pursue this objective with Iran,” said the report.
Sept. 25, 2019: The IAEA found that Iran had breached the JCPOA again by using advanced centrifuges to enrich uranium. The 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.” Each cascade could include up to 20 centrifuges. 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. 11, 2019: In a quarterly report, the IAEA said that Iran had breached the 2015 nuclear deal by increasing its stockpile of enriched uranium. The watchdog also reported that its inspectors had found traces of uranium “at a location in Iran not declared to the agency.” The IAEA confirmed Iran had started enriching uranium at the underground Fordo facility. The JCPOA had banned uranium enrichment at the site until 2031.
Nov. 18, 2019: The IAEA confirmed that Iran had breached the 130 metric ton limit on heavy water set by the JCPOA. Heavy water allows unenriched uranium to be used as a fuel in specially designed nuclear reactors. Heavy water reactors also produce plutonium as a waste fuel, which can then be reprocessed for use in plutonium bombs.
March 3, 2020: 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.
March 3, 2020: The IAEA said that Iran had refused to grant inspectors access to three sites of interest. The sites were suspected to have been part of the Iran’s nuclear program in the early 2000s. The watchdog believed that Iran had tried “to sanitize part of the location” to obscure its past nuclear activities. “Iran is curtailing the ability of the agency to do its work,” IAEA Director General Rafael Grossi said.
June 5, 2020: The IAEA said that Iran’s stockpile of enriched uranium had grown far above the amount permitted by the JCPOA. Iran possessed 1,571.6 kg of low enriched uranium, a 50 percent increase since February. Its stockpile of heavy water remained slightly above the 130 metric ton limit set by the JCPOA.
June 5, 2020: Iran blocked IAEA inspectors from accessing two sites, the U.N. watchdog reported. The agency said that the sites may have been used for the storage and explosive testing of undeclared nuclear materials in the early 2000s. “The Agency notes with serious concern that, for over four months, Iran has denied access to the Agency…to two locations and, for almost a year, has not engaged in substantive discussions to clarify Agency questions related to possible undeclared nuclear material and nuclear-related activities in Iran,” the report said.
June 19, 2020: The IAEA Board of Governors 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.
Aug. 26, 2020: The IAEA and Iran released a joint statement which said that Iran agreed to provide the IAEA with access to the two suspect sites and facilitate verification activities.
Sept. 4, 2020: In a quarterly report, the IAEA said that Iran’s stockpile of low-enriched uranium reached 2,105 kilograms, or about 10 times more than the JCPOA limit. The stockpile had grown some 544 kilograms since the last quarterly report, released in June. Iran also began operating slightly more advanced centrifuges, but not enough shorten its breakout time, which remained three to four months. When Iran was in full compliance with the JCPOA, its breakout time had been 12 months.
In a separate safeguards report, the U.N. watchdog confirmed that it had visited one undeclared nuclear site to take environmental samples. The agency said it would visit another suspect site later in September.
Nov. 11, 2020: The IAEA reported that Iran’s stockpile of low-enriched uranium reached 2,443 kg (2.7 tons), or about 12 times more than the JCPOA limit. The stockpile had grown by 337.5 kg since the prior report released in September, a slower rate of growth than previously recorded. Iran installed 174 IR-2M centrifuges and conducted tests of three IR-4 advanced centrifuges.
The IAEA found Iran’s explanations for uranium particles detected at an undeclared nuclear site to be “unsatisfactory” and “not technically credible.”
Nov. 17, 2020: The IAEA reported that Iran began feeding uranium gas into 174 IR-2M advanced centrifuges at Natanz, the IAEA .
Dec. 4, 2020: Iran informed the IAEA that it would install three new cascades of advanced centrifuges. Each cascade was made up of more than 150 centrifuges.
Jan. 4, 2021: 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, 2021: 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, 2021: 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. 17, 2021: 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, 2021: 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, 2021: 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, 2021: 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, 2021: 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.