Uranium Deal Talks May Not Resolve Iran’s Hidden Stockpile Problem

Iran’s enriched uranium is expected to be central to talks with the United States, but the deeper issue is that no one can say with confidence how much enriched uranium Iran currently has, where it is stored, or whether more was produced while monitoring was cut off. A U.S. official said the emerging deal is supposed to destroy high-enriched uranium and remove it from Iran, while Foreign Minister Abbas Araghchi said Tehran wants the material to remain in the country after it is diluted to a lower enrichment level.

The International Atomic Energy Agency’s last reference point was June 13, 2025, when it estimated that Iran held 440.9 kilograms of uranium enriched to 60 percent, including 432.9 kilograms previously verified by inspectors. Since then, the monitoring chain has been broken, and the agency says it cannot update the balance, determine what happened to the stockpile, or confirm that enrichment, including research and development, has stopped. Its latest report says it has no information on the current size, composition, or location of the enriched uranium stockpile.

Inspectors have not been allowed into any of Iran’s four declared enrichment sites, and at one of them they have never been admitted since Tehran announced it. The IAEA describes the situation as a “loss of continuity of knowledge,” meaning the chain tracking each gram of uranium from production to its present location has been broken. Cameras restored now could only record future activity, not reconstruct the months without oversight.

The same problem extends to centrifuges and undeclared activity. Since February 2021, the agency has not had regular access to facilities where centrifuge components were produced, assembled, and tested, and it says it cannot report how many centrifuges Iran now possesses or confirm that production and assembly stopped. Iran also does not apply the Additional Protocol or amended Code 3.1, both of which would expand inspections and require earlier notice of new nuclear facilities. The article says only a much broader verification regime, full declarations, access to all sites and storage areas, environmental sampling, and restored IAEA tools, could close the gap; otherwise, diluting declared material in Isfahan would not prove that no additional stockpile remains.