The Director General of the International Atomic Energy Agency (IAEA) assessed that the bulk of Iran’s highly enriched uranium stockpile is probably still located at the Isfahan nuclear complex. The site was struck by airstrikes last year and experienced relatively lighter attacks during the recent US-Israeli military campaign.

Rafael Grossi shared the assessment in an interview with The Associated Press. He noted that the IAEA possesses satellite imagery documenting the impact of the latest strikes on Iranian nuclear facilities and continues to gather additional information.

Inspections by the IAEA at Isfahan ceased when Israel initiated a 12-day war in June of last year, during which the United States conducted strikes on three Iranian nuclear sites. Tehran at the time suspended cooperation with the IAEA and barred inspectors from visiting the damaged sites, accusing the agency of bias and failing to condemn the attacks.

An agreement announced in September between Iran and the IAEA, intended to resume inspections and uranium accounting, has since been declared void by Tehran after Britain, France, and Germany triggered the return of UN sanctions previously lifted under the 2015 nuclear deal.

The UN nuclear watchdog estimates that a large portion of Iran’s highly enriched uranium “was stored there in June 2025 when the 12-day war broke out, and it has been there ever since,” Grossi told AP.

“We haven’t been able to inspect or to reject that the material is there and that the seals – the IAEA seals – remain there,” he said. “I hope we’ll be able to do that, so what I tell you is our best estimate.”

Satellite images captured by Airbus on June 9, 2025, just prior to the outbreak of last year’s war, show a truck carrying 18 blue containers entering a tunnel at the Isfahan Nuclear Technology Center. Those containers are believed to hold highly enriched uranium and are likely still inside the facility.

Grossi added that the IAEA also seeks access to Iran’s nuclear sites at Natanz and Fordow, where additional nuclear material is present.

Iran currently possesses 440.9 kilograms of uranium enriched to 60 percent purity, a level only a short technical step away from weapons-grade 90 percent enrichment. Grossi previously indicated that the IAEA believes roughly 200 kilograms of this material is stored in tunnels at the Isfahan site.

Grossi emphasized that the critical objective remains ensuring “that material leaves Iran” or is down-blended to lower enrichment levels.