The International Atomic Energy Agency (IAEA) has said it is “increasingly concerned” by an underground Iranian uranium-enrichment facility that its inspectors were not permitted to assess.
The United Nations’ nuclear watchdog said it “does not know” the Isfahan Fuel Enrichment Plant’s [IFEP] “exact location, status for safeguard purposes or whether it contains nuclear material” in a confidential report seen by Reuters.
A US. Air Force B-2 Spirt assigned to the 509th Bomb Wing, Whiteman Air Force Base receives fuel from a U.S. Air Force KC-135 assigned to the 185th Air Refueling Wing, Iowa Air National Guard in the sky over northwest Missouri on August 29, 2018. U.S. Air National Guard photo by Senior Master Sgt. Vincent De Groot
Pilots with the 131st Bomb Wing conduct pre-flight checks in a B-2 Spirit stealth bomber at Whiteman Air Force Base, Missouri, June 6, 2024. The B-2 is a multi-role bomber capable of delivering both conventional and nuclear munitions anywhere on the globe through previously impenetrable defenses. (U.S. Air National Guard photo by Master Sgt. John E. Hillier)
Iran’s nuclear program has been one of the justifications for the conflict for President Donald Trump, who has repeatedly said that Tehran must never obtain a nuclear weapon.
Isfahan Plant Remains Beyond Inspectors’ Reach
Iran declared IFEP to the nuclear watchdog in June 2025, shortly before a 12-day U.S.-Israeli bombing campaign started. A planned visit by inspectors was curtailed when the short-lived conflict began.
Tehran has not permitted the IAEA to visit any of its nuclear facilities bombed last year. The agency is unaware of their specific whereabouts or of ongoing activity at the underground site.
In its confidential report, the IAEA said the “lack of information” about the nuclear material at IFEP and lack of access by inspectors to verify “is a matter of serious proliferation concern,” adding that the issue “needs to be rectified with the utmost urgency.”
IFEP Could Be Home of Iran’s Bomb-Grade Uranium
The site is home to almost half of Iran’s uranium enriched to as much as 60% purity.
Although a purity of 90% is considered weapons-grade, the step up from 60% to 90% is a much shorter technical leap, as much of the complex infrastructure is already in place.
Under a nuclear treaty Tehran signed in 2015, Iran is permitted to maintain a stockpile of no more than 300kg and enrich uranium to 3.67% purity.
Both levels have since been exceeded.
Before last year’s strikes, the country had an estimated 441kg enriched to 60%.
In a report released to IAEA members the day before the Iran war began, the agency said that allowing inspections was “indispensable and urgent.”
“While the agency acknowledged that the military attacks on Iran’s nuclear facilities had created an unprecedented situation, it must conduct verification activities in Iran without any further delay,” the IAEA reportedly wrote.
Assumptions on Iran’s Uranium Storage
In March this year, IAEA Director General Rafael Grossi said that much of this enriched uranium is stored in IFEP within a tunnel complex that survived the U.S.-Israeli bombing campaign.
He said the agency believed that much of Iran’s enriched uranium was stored in IFEP, while some elsewhere was destroyed last June.
“The widespread assumption is that the material is still there. So, we haven’t seen — and, not only us, I think in general all those observing the facility through satellite imagery and other means to see what’s going on there — movement indicating that the material could have been transferred,” Grossi told reporters.
The watchdog chief added that some of Iran’s 60%-enriched uranium remained at Natanz, a site that was targeted in the June 2025 strikes.
Trump’s Nuclear Justification for the Iran War
President Trump has repeatedly defended his decision to go to war with Iran despite the knock-on effect of increased commodity prices as a result of Tehran’s ongoing closure of the Strait of Hormuz.
Speaking to reporters at Mar-a-Lago on Saturday, October 31, Trump said the U.S. still had “one or two” targets to address in Iran. “We’ve knocked out their nuclear [program],” Trump said. “We still have to take care of, I would say, one or two sites, but we can do that in 10 minutes.”
A U.S. Air Force B-2 Spirit is prepared for operations ahead of Operation MIDNIGHT HAMMER at Whiteman Air Force Base, Missouri, June 2025.
He added: “You probably could look at Pickaxe Mountain, and you have to take care of that. We can do that all very quickly.”
Pickaxe Mountain is a suspected underground nuclear complex in the Karkas Mountains in Iran’s Isfahan province.
The heavily fortified site is situated approximately one mile south of the Natanz nuclear complex.
The Iranian government denied that any nuclear work is carried out there.
However, following a dismal midterm election for the Republican Party, which Vice President J.D. Vance blamed firmly on the war, U.S. strategy has shifted to preserving the status quo of maintaining economic pressure on Iran through sanctions, frozen funds, and an ongoing naval blockade of the country’s ports.
About the Author: Shay Bottomley
Shay Bottomley is a British journalist. He has written for the Western Standard, Business Insider, Maidenhead Advertiser, Slough Express, Windsor Express, Berkshire Live and Southend Echo.
