Iran’s nuclear program has once again become the focus of international scrutiny, as a confidential report from the United Nations’ nuclear watchdog reveals a significant increase in Tehran’s stockpile of near weapons-grade uranium just before Israel’s military attack in June. The Vienna-based International Atomic Energy Agency (IAEA) disclosed that, as of June 13, 2025—the day before Israel’s strikes—Iran possessed 440.9 kilograms (about 972 pounds) of uranium enriched up to 60%. This marks a 32.3-kilogram (71.2-pound) increase since the agency’s last report in May, according to The Associated Press and other media outlets.
The IAEA’s findings are based on data provided by Iran, verification activities conducted between May 17 and June 12, 2025, and estimates derived from the operation of relevant nuclear facilities. The agency emphasized that uranium enriched to 60% is only a short, technical step away from weapons-grade levels of 90%. For context, the IAEA notes that approximately 93 pounds (about 42 kilograms) of uranium enriched to 60% would be sufficient, if further enriched, to produce a single atomic bomb.
This latest disclosure comes against a backdrop of escalating tensions between Iran, Israel, and the broader international community. The period leading up to the Israeli attack saw Iran’s uranium stockpile growing steadily, often in monthly increments of a few dozen kilograms. The IAEA’s last reports before June reflected similar month-to-month increases, typically ranging from 15 to 30 kilograms. By June 13, Iran’s total enriched uranium stockpile had ballooned to 21,770.4 pounds (9,870 kilograms), an increase of 1,382.9 pounds (627 kilograms) since May.
However, the true extent of Iran’s current nuclear capabilities remains shrouded in uncertainty. Following the Israeli and U.S. strikes on Iranian nuclear facilities in June, the IAEA has been unable to conduct inspections or verify Iran’s declarations about its near-weapons-grade uranium stockpile for over two and a half months—a gap that the agency calls “a matter of serious concern.” According to the IAEA report, “since June 13, it has not been able to conduct the in-field activities required to collect and verify Iran’s declarations used to estimate the changes to the previously reported stockpile.”
The only exception has been the Bushehr Nuclear Power Plant, which operates with Russian technical assistance. Inspectors were present for a fuel replacement at Bushehr on August 27 and 28, but no other sites have been inspected since the outbreak of hostilities. This limited access has left the IAEA and the global community in the dark about the current state of Iran’s enriched uranium stocks and the potential risks they pose.
The breakdown in cooperation between Iran and the IAEA stems from a series of rapid developments following the June attacks. On July 2, Iranian President Masoud Pezeshkian signed a law—passed by the Iranian Parliament—suspending all cooperation with the agency. The IAEA’s report described Tehran’s move as “deeply regrettable,” underscoring that Iran is legally obliged to cooperate under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).
Diplomatic efforts to restore oversight have continued, albeit with limited progress. On August 11, a technical team from the IAEA traveled to Tehran for discussions with Iranian officials. Three days later, Iran sent a letter outlining a draft “new arrangement” for inspections. Under this proposal, the IAEA would have to submit requests for inspections of undamaged nuclear sites on a case-by-case basis. For sites that were damaged in the attacks, Iran offered to provide the agency with a report “up to one month after the finalization of this Arrangement,” after which new terms for cooperation would be negotiated.
The IAEA has insisted that any new inspection arrangement must comply with the nuclear safeguards agreement Tehran has with the agency. Talks between Iran and the IAEA are set to resume in Vienna in the coming days, with both sides expressing hope for a breakthrough. IAEA Director General Rafael Grossi said the agency is “trying to hold talks with Iran in the next few days,” adding that the goal is to determine how inspections can be resumed.
The timing of these developments could hardly be more critical. On August 28, France, Germany, and the United Kingdom initiated a 30-day process to reimpose United Nations sanctions on Iran—a move known as the “snapback mechanism.” This process, designed to be veto-proof at the UN, was built into the 2015 nuclear deal to ensure compliance and could see sanctions return by late September unless a diplomatic solution is reached. European nations have signaled a willingness to extend the deadline if Iran resumes direct negotiations with the United States, allows IAEA inspectors access to its nuclear sites, and fully accounts for the over 400 kilograms of highly enriched uranium the agency says it possesses. As of now, Iran has met none of these conditions.
In the midst of this standoff, Iran has accused the IAEA of providing Israel with a pretext for its attacks. After the UN nuclear watchdog’s 35-nation board of governors passed a resolution on June 12 formally declaring Tehran in breach of its non-proliferation obligations—the first such declaration in nearly two decades—Iran claimed the move was “clearly designed to produce a crisis.” The IAEA has rejected this accusation, maintaining that its actions are guided solely by its mandate to uphold nuclear non-proliferation.
The war between Israel and Iran, which erupted in June and ended on June 24 after U.S. intervention, resulted in the deaths of senior Iranian military commanders and hundreds of others. Iran retaliated with missile barrages against Israeli military sites, infrastructure, and cities. Amid the chaos, Iran reportedly moved its uranium stockpile—enough for six to nine atomic bombs if enriched to 90%—away from main sites before the strikes, further complicating international efforts to assess the program’s status.
Despite the mounting pressure, Iran has insisted it remains committed to diplomacy, but has warned it will not negotiate “under threats or coercion.” The coming days will be pivotal, as the world watches to see whether diplomatic engagement can restore oversight and avert a new nuclear crisis in the Middle East. The stakes, both for regional stability and global non-proliferation efforts, could hardly be higher.
As the 30-day clock ticks toward possible renewed sanctions and the IAEA prepares for fresh negotiations in Vienna, the international community faces a moment of reckoning. The outcome will determine not only the future of Iran’s nuclear program but also the credibility of the global nuclear monitoring regime itself.
