The whereabouts of Iran's highly enriched uranium, material potentially sufficient for at least ten nuclear bombs, remain a significant concern for the United States, with diplomatic efforts now focused on convincing Tehran to relinquish the stockpile in exchange for sanctions relief.
A substantial portion of Iran's enriched uranium is believed to be stored deep underground, potentially beyond the reach of even powerful bunker-buster bombs. Retrieving this material presents enormous risks, including the potential for extreme toxicity if exposed to moisture. U.S. Secretary of State Marco Rubio highlighted the sanctions regime against Iran as directly linked to its possession of this enriched uranium and its nuclear activities, suggesting that relinquishing these would lead to sanctions relief.
According to the International Atomic Energy Agency (IAEA), as of June 2025, Iran possessed approximately 970 pounds of uranium enriched to 60 percent. This fissile material, often stored in canisters, could be dispersed across multiple locations, making its exact location unknown without comprehensive IAEA inspections. Experts believe a primary location is likely near the Isfahan nuclear complex, buried deep within a mountain and thus potentially inaccessible to conventional aerial bombardment. Recent satellite imagery indicates efforts by Iran to obscure or protect entrances to this site following airstrikes.
Additional enriched uranium may be located at Iran's largest enrichment site, Natanz, and a nearby, heavily fortified underground facility known as Pickaxe Mountain. Both sites have reportedly been targeted in past military actions, with subsequent modifications suggesting Iran is reinforcing them against potential future attacks. The Fordo facility, previously damaged by U.S. strikes, may also hold remnants, though its operational capacity is severely diminished. The possibility of further unknown storage locations complicates any strategy for retrieval or disposal.
Beyond the 60 percent enriched uranium, Iran maintains a larger overall stockpile of enriched uranium, totaling over 19,930 pounds across various enrichment levels. While converting this material to weapons-grade would require time, Iran's continued operation of enrichment facilities preserves its potential capability to do so. The dispersed and deeply buried nature of Iran's nuclear materials presents a formidable challenge for international efforts to prevent nuclear proliferation.
