Iran has stored some of its most highly enriched uranium in an underground tunnel complex at its key Isfahan nuclear facility, the International Atomic Energy Agency disclosed in a confidential report, according to Reuters. The disclosure marks the first time the UN nuclear watchdog has publicly pinpointed the location of Iran’s near-bomb-grade stockpile.The tunnel complex’s entrance was targeted in US and Israeli strikes in June, but the facility appears largely undamaged, according to diplomats.As per the report, the Isfahan site, a cornerstone of Iran’s nuclear infrastructure, houses uranium enriched to 60% purity, perilously close to the 90% threshold for nuclear weapons. According to experts, it could be rapidly converted into weapons-grade material sufficient for multiple bombsIAEA has also confirmed “technical discussions” in Vienna next week, beginning Monday, between Iran and the United States to hammer out safeguards implementation.The report said, “Technical discussions will take place in Vienna in the week beginning 2 March 2026.” It further added, “a successful outcome of Iran-US negotiations would have a positive impact on the effective implementation of safeguards in Iran,” news agency AFP reported.The disclosure comes at a time of heightened friction between Washington and Tehran. The two nations recently held talks in Geneva, mediated by Oman, which was also described as “most intense” by Iran’s foreign minister, Abbas Araghchi, as he added that the negotiators made very good progressThe United States has stepped up its military presence across the Middle East, while President Donald Trump has repeatedly warned Iran of “serious consequences” if diplomatic efforts collapse.Tehran continues to insist that its nuclear programme is strictly for civilian purposes. However, US officials remain wary, suspecting that Iran could be positioning itself to restore or expand elements of its nuclear capabilities if negotiations falter.Diplomatic failure could further destabilise an already volatile region.