Israeli Intelligence Reports Iran Moved Thousands of Centrifuges to Deep Underground Site at Mount Makush

Israeli intelligence agencies believe that Iran transferred thousands of uranium enrichment centrifuges to deep underground tunnels inside Mount Makush during the past autumn. This information was shared with the United States following the 12-day conflict in June 2025, during which Israeli and American airstrikes targeted Iran's three main nuclear sites. A senior Israeli military official expressed concerns to the Wall Street Journal that the recent airstrikes did not sufficiently target nuclear weapons-related facilities, including those at Mount Makush, stating, "There is still work to be done."

Mount Makush, located about 1.5 kilometers south of Natanz, has been monitored by the US and Israel for years and is believed to be a subterranean replacement for a centrifuge assembly plant severely damaged in a 2020 explosion, suspected to be sabotage. The International Institute for Strategic Studies reported ongoing activity at the site over the last 15 months, including truck movements, tunnel reinforcements, and new security installations. Experts estimate the underground complex extends 90 to 137 meters below solid rock and could house multiple nuclear-related facilities.

US National Security Council official Nate Swanson highlighted the risks of undisclosed nuclear activity at such a fortified underground site, calling secret nuclear breakthroughs "the worst-case scenario." He emphasized the need for the International Atomic Energy Agency (IAEA) to inspect the site. Iran has denied pursuing nuclear weapons but has produced approximately 450 kilograms of uranium enriched to 60%, near weapons-grade levels. The IAEA has not been granted access to Mount Makush and has received no information about its operations.

Following the June 2025 conflict, Iran may have relocated surviving centrifuges to Mount Makush to protect them from destruction. The exact origin of these centrifuges remains unclear. Israeli Prime Minister Benjamin Netanyahu has urged then-US President Donald Trump to resume comprehensive strikes on Iran to further delay its nuclear weapons program. Trump recently acknowledged Mount Makush as a potential target for a major strike. Iran's Foreign Minister Abbas Araghchi and the IAEA declined to comment on the reports.