Iran’s Axe Mountain nuclear site draws scrutiny after Trump strike threat

Iran’s "Axe Mountain" nuclear site in central Iran has come under heightened international attention after former US President Donald Trump threatened to strike it, calling it a "potential target" during remarks on July 21 while hosting Lebanese President Joseph Aoun at the White House, according to France’s Courrier International magazine.

The magazine, citing Israeli intelligence sources, reported that Iran moved hundreds of uranium enrichment centrifuges into deep tunnels beneath the mountain in autumn last year, following strikes on three major Iranian nuclear sites in June 2025. CNN, also quoting Israeli sources, said Tehran transferred part of its 400-kilogram stockpile of highly enriched uranium to the same location.

Site details and recent developments

Courrier International explained that Axe Mountain is a heavily fortified facility near the Natanz nuclear site, which was struck in June and March 2025 by Israel and the United States. Iran began building the site in 2020, announcing to the International Atomic Energy Agency that it would serve as a centrifuge assembly plant. However, the site has remained shrouded in secrecy and is not yet operational, according to CNN.

The Institute for Science and International Security (ISIS) has observed increased activity at the site, including truck movements, tunnel reinforcements, and the construction of additional security barriers. An ISIS expert noted that the complex appears much larger than needed for centrifuge assembly alone, raising questions about its true purpose.

Challenges of targeting the site and reactions

According to Courrier International and CNN, the site’s depth—over 100 meters underground—makes it extremely difficult to destroy, even with bunker-busting bombs. Experts believe any attack would likely only damage the entrance tunnels without significantly affecting the facility’s core capabilities. Iran, for its part, has warned that any attack on its nuclear sites would represent a serious regional escalation.

Ali Vaez, Iran specialist at the International Crisis Group, said the timing of these leaks appears aimed at raising tensions and preventing a return to diplomacy.

Iranian authorities, speaking to CNN, have denied any undeclared nuclear activity at the site.