UN Nuclear Chief Warns of ‘Significant’ Damage to Iran’s Facilities, Urges Return to Talks

The head of the United Nations nuclear watchdog has warned that recent US and Israeli military strikes have caused “very significant” damage to Iran’s nuclear facilities, escalating global concerns over nuclear safety and prompting renewed calls for diplomacy, Al Jazeera reports.

Speaking at an emergency session of the International Atomic Energy Agency (IAEA) board on Monday, Director General Rafael Grossi confirmed visible destruction at multiple nuclear sites in Iran, including Fordow, Natanz, and Isfahan. The facilities were targeted by US airstrikes over the weekend following similar action by Israel earlier this month.

Grossi said the Fordow enrichment site, a key pillar of Iran’s nuclear program, sustained major surface and suspected underground damage from US ground-penetrating bombs. While the IAEA has not yet been granted access to conduct a full assessment, Grossi stressed that “the explosive payload and the vibration-sensitive nature of centrifuges” suggest the impact is likely to be substantial.

At Natanz, a fuel enrichment plant was hit, and at Isfahan, buildings related to uranium conversion and tunnel entrances used for storage were damaged, Grossi said. Despite the strikes, no radiation leaks have been reported to date.

The IAEA chief reiterated that military action against nuclear infrastructure sets a dangerous precedent.

“Armed attacks on nuclear facilities should never take place,” he said, while stopping short of directly condemning the US or Israel.

Grossi also called on all parties—particularly Iran and the United States—to return to negotiations, warning that continued escalation could lead to “unimaginable” consequences.

In response to the strikes, Iran has sharply criticized the IAEA, accusing it of providing political cover for the attacks. Tehran alleges that past IAEA reports were biased and used by Israel and the US to justify military action. Iranian officials are now considering withdrawing from the Nuclear Non-Proliferation Treaty (NPT), a move that would mark a major shift in the country’s engagement with the global nuclear framework.

Iran’s envoy to the IAEA said the strikes had “shattered” the integrity of the NPT and vowed retaliation under international law. Iranian lawmakers are also backing proposals to suspend cooperation with the IAEA altogether.

Grossi acknowledged these tensions but appealed for continued dialogue, expressing willingness to visit Iran personally.

“I’m ready to travel immediately to Iran. We need to keep working together despite existing differences,” he said.

Former IAEA official Tariq Rauf noted that while Iran’s enrichment infrastructure has been seriously impaired, the country still holds roughly 9,000 kilograms of enriched uranium—some of it enriched up to 60 percent—which remains unverified until inspectors are allowed back in.