The IAEA warned that lack of access to an underground plant near Isfahan poses serious proliferation risks.
The United Nations nuclear watchdog warned on Friday that Iran must urgently allow inspectors back into its atomic sites, pointing to an uninspected underground enrichment facility near the city of Isfahan.
The International Atomic Energy Agency circulated a report to member states calling on Tehran to restore access for monitoring teams, Al Jazeera reported. Iran told the agency that it cannot permit inspections under the present security conditions, citing continuing military threats from the United States.
Uncertainty at the Isfahan facility
The watchdog expressed specific alarm over the Isfahan Fuel Enrichment Plant in central Iran. Tehran declared the underground facility in 2025, but inspectors have never received permission to enter it.
The agency does not know the exact location of the plant, whether nuclear material is stored inside it, or its current status under international safeguards, according to BBC News. While the report stopped short of saying uranium enrichment is happening there, the agency noted that it cannot independently establish what is taking place without physical access.
The broader nuclear complex at Isfahan suffered extensive damage during strikes carried out by the US and Israel in June 2025, particularly to structures above the ground. The condition of the underground portions remains unknown. The agency believes that much of Iran’s stockpile of highly enriched uranium was stored at the site.
Why the stockpile matters
Under the terms of a 2015 agreement, Iran agreed to keep its enriched uranium stockpile capped at 300 kilograms and hold its enrichment level to 3.67% purity. Over time, Iran went well beyond both restrictions.
Before the June 2025 military strikes, Iran had gathered an estimated 441 kilograms of uranium enriched to 60% purity, a level close to weapons grade. The agency reported that it has been unable to confirm the status of that near-weapons-grade stockpile since the bombing raids.
The United States and Israel stated that their strikes were meant to stop Iran from producing nuclear weapons. Iran has repeatedly denied that it seeks a bomb, maintaining that its nuclear program exists solely for peaceful civilian purposes. International diplomats have pushed for Iran to reduce uranium enrichment as part of broader efforts to resolve regional conflicts.
How access broke down
Iran told the IAEA about its intention to build the Isfahan Fuel Enrichment Plant on 12 June 2025. That declaration followed an IAEA resolution declaring that Iran had not satisfied its safeguards obligations. Tehran initially agreed to let inspectors visit the location, but that visit was called off when Israel began hitting Iranian nuclear sites the following day. The US joined those military strikes later that month.
The IAEA pulled its inspectors out of the country for safety reasons after the attacks began. Iran’s parliament subsequently approved legislation suspending cooperation with the agency, permitting only very limited monitoring visits since then.
Roughly a year ago, the agency made a similar plea to Iran for access. At that point, inspectors had visited only some of the 13 sites that avoided damage in the attacks, while visiting none of the seven sites that took hits. In its latest findings, the agency said its lack of information is a matter of proliferation concern that needs to be rectified with the utmost urgency.
What happens next
The IAEA stated that it is prepared to restart safeguards work across Iran on short notice. Agency Director General Rafael Grossi asked Tehran to adopt limited technical steps that could enable inspectors to visit sites and begin rebuilding routine monitoring.
Iranian Foreign Ministry spokesperson Esmaeil Baghaei told reporters at a news conference in Tehran on Monday that Iran remains committed to the Nuclear Non-Proliferation Treaty. Even so, he laid blame on American and Israeli attacks for the breakdown in cooperation.
Iran notified the IAEA this month that negotiations on restoring access cannot proceed while the US president continues making public threats of armed aggression against the country. Tehran added that the issue will stay unresolved until the root causes are resolved and standard conditions for safeguards work return.
