The United Nations atomic watchdog said it’s observed construction activity at Iran’s Pickaxe Mountain, a heavily-fortified site suspected of housing nuclear-related activities.
The International Atomic Energy Agency has yet to inspect inside the tunnel complex but remote imagery indicates new movement at the site just south of Tehran’s main uranium-enrichment plant, IAEA Director General Rafael Mariano Grossi said yesterday in an interview with Bloomberg Televsion.
US President Donald Trump has drawn attention to the site in public comments at least twice in the last week.
“There are some indications that there is movement around this construction site,” Grossi said.
“We don’t have any concrete information as to activities that may be taking place there.”
Grossi commented after the IAEA’s board of governors referred Iran’s nuclear file to the UN Security Council for non-compliance with requirements related to its atomic activities.
Inspectors haven’t verified the state or location of Iran’s inventory of near-bomb-grade uranium since June 2025, when Israel and the US attacked its sprawling nuclear facilities.
“We notice there’s a little activity at Pickaxe,” Trump said Wednesday at a Republican rally.
“I would advise Iran not to get cute because we will have to hit them very hard.”
Activity at the Pickaxe site, located in the Zagros Mountains 220 km south of Tehran, was initiated after saboteurs attacked an Iranian centrifuge workshop six years ago.
“They said at the time, ‘we are going to put everything in tunnels, inside a mountain’.” Grossi said.
“This was going to be impermeable and protected from attacks.”
Israel and the US want Iran to dismantle its centrifuge programme and cease enriching uranium.
Centrifuges are the fast-spinning machines separating uranium isotopes and are a critical technology in the making of nuclear fuel for power or weapons.
The resolution of censure passed against Iran late Wednesday could open the possibility of new military strikes against Iranian nuclear facilities.
Trump has repeatedly said preventing Tehran from building a nuclear weapon is the reason for going to war with Iran.
In a separate diplomatic note circulated this week, Iran cautioned western countries against turning the IAEA into a tool of war.
Tehran’s envoy highlighted the precedent set in June 2025, when Israel began attacks on Iran a day after the organisation found the Islamic Republic in non-compliance of its nuclear obligations.
“The aggressions of the Israeli regime and America against Iran just a few hours after its adoption, are solid proofs of the sponsors’ hidden agenda,” Iran’s IAEA envoy wrote in the 11-page document, which urged diplomats to “condemn the unlawful attacks.”
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