A recently identified underground structure at Iran's Natanz nuclear complex may be linked to the country's uranium enrichment activities, according to a report by the Institute for Science and International Security (ISIS). The facility, partially submerged and bunkered, was reportedly constructed between 2010 and 2017 and may not have been a target during military actions in 2025 and 2026.
ISIS stated that the facility "was likely intended to serve as uranium hexafluoride… storage facility to support large-scale uranium enrichment at the Natanz Fuel Enrichment Plant." The report noted that no vehicle activity has been observed at the site in available satellite imagery since the June 2025 war, suggesting it remained intact.
This revelation comes amid ongoing concerns about Iran's nuclear ambitions. In April 2025, ISIS reported that Iran had nearly doubled its stock of 60% enriched uranium, raising suspicions that the country was moving towards developing nuclear weapons. Uranium enrichment is a critical step in the production of fissile material for nuclear arms.
While the U.S. and Israeli strikes in 2025 and 2026, including "Operation Midnight Hammer," significantly impacted Iran's nuclear infrastructure, the status of this specific bunkered facility raises questions. Jason Brodsky, policy director at United Against Nuclear Iran, commented that "the report assesses the structure at the Natanz nuclear facility was not targeted during Operations Midnight Hammer and Epic Fury." He added that without IAEA inspections of such facilities, Washington and Jerusalem must rely on their own intelligence.
An International Atomic Energy Agency (IAEA) spokesperson indicated that the building in question was known to the agency and had been regularly inspected prior to mid-2025.
The U.S. has maintained a firm stance against Iran possessing nuclear weapons. A White House spokesperson asserted that "Iran’s nuclear facilities were totally obliterated during Operation Midnight Hammer." The administration has also implemented extensive economic sanctions, including "Operation Economic Outcast," described as the most significant financial offensive against an adversary, aimed at isolating the regime and hindering its ability to rebuild its nuclear program.
Former President Trump previously warned that Iran would "absolutely" use a nuclear weapon if obtained. U.S. Treasury Secretary Scott Bessent announced a comprehensive economic pressure campaign against Iran, which experts suggest could contribute to the dissolution of the current regime.