IAEA Refers Iran To UN Security Council As Grossi Flags New Construction At Pickaxe Mountain

The International Atomic Energy Agency's Board of Governors voted on Thursday to refer Iran's nuclear file to the United Nations Security Council, citing continued non-compliance with the agency's safeguards requirements, in one of the most consequential diplomatic escalations of the year-long standoff between Tehran and the West.

The referral came the same day IAEA Director General Rafael Mariano Grossi told Bloomberg Television that remote satellite imagery had picked up fresh construction activity at Iran's Pickaxe Mountain facility, a fortified underground complex built into a mountain roughly two kilometres south of the Natanz uranium-enrichment plant. Grossi said inspectors have not been able to enter the tunnel complex and therefore cannot confirm what is being built, but described "some indications that there is movement around this construction site."

A Site Built To Survive Attack

Pickaxe Mountain, located in Iran's Zagros range, was developed after an earlier strike on an Iranian centrifuge workshop, with Tehran moving sensitive nuclear-related infrastructure into tunnels designed to withstand aerial bombardment. Independent analysis cited by international broadcasters, drawing on commercial satellite imagery reviewed by the Center for Strategic and International Studies, found that construction activity at the site in 2026 has been higher than at any point previously observed, though analysts cautioned the facility does not yet appear capable of enrichment work.

Grossi's comments followed repeated warnings from US President Donald Trump, who told a Republican rally in Texas this week that Washington had also observed activity at the site and cautioned Iran against further work there, saying the United States would respond forcefully if enrichment-related activity continued. Trump has separately said the US military is developing a new bunker-buster munition intended to succeed the GBU-57A/B Massive Ordnance Penetrator, capable of striking more deeply buried facilities than current weapons allow.

Inspectors Still In The Dark On Uranium Stockpile

Compounding the concern among Western governments, the IAEA has said it has not been able to verify the location or condition of Iran's stockpile of near weapons-grade enriched uranium since strikes on Iranian nuclear sites in June last year. That gap in visibility has been central to the case pressed by the United States and its allies for referring Tehran's file to the Security Council, a step that could pave the way for renewed sanctions or other punitive measures, and one Iran has strongly objected to.

Iran's mission to the IAEA warned this week against using the agency "as an instrument of war," pointing to the timing of the 2025 strikes, which came shortly after the IAEA had found Iran in violation of its nuclear obligations, and calling on diplomats to condemn those attacks rather than escalate further pressure on Tehran.

Wider Nuclear Anxiety

Grossi used the occasion to voice broader concern about global nuclear stability, saying more countries are now reconsidering whether to acquire or even use nuclear weapons, and linking that shift to a more conflict-prone international environment. He warned that continued proliferation pressures could eventually increase the risk of nuclear weapons being used somewhere in the world.

The Security Council referral now puts Iran's nuclear programme squarely before the UN's most powerful body at a moment when the broader US-Iran conflict, and its knock-on effects across Gulf shipping and regional security, show no signs of abating. How Tehran responds to the referral, and whether it grants IAEA inspectors renewed access to Pickaxe Mountain, is likely to shape the diplomatic and military trajectory of the standoff in the weeks ahead.

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