Breaking news: Iran has reportedly moved to seal off parts of its highly enriched uranium stockpile by collapsing tunnels and placing explosive mines at entrances, a development that could complicate the emerging U.S.-Iran deal just as negotiators appear close to a signing.
The Jerusalem Post and i24NEWS, citing CNN and sources familiar with U.S. intelligence, reported Saturday that Iran has sharply increased efforts to secure its near weapons-grade uranium cache in recent weeks. The reports said access to the material is now more dangerous and time-consuming than it was a month ago.
Why the tunnel report matters
The timing is the key. U.S. and Iranian officials are already trading conflicting claims over what a possible agreement would require. Washington has said any deal must address Iran’s enriched uranium stockpile. Tehran has pushed back on details and timing, even as mediators and President Donald Trump say a deal could be close.
The reported fortifications could turn a diplomatic promise into a much harder verification problem. If tunnel entrances are mined or deliberately collapsed, outside inspectors and technical teams would face a slower process to confirm what material remains, where it is stored, and whether it can be safely removed.
The Isfahan stockpile is central
The Isfahan nuclear complex has been a major focus because the International Atomic Energy Agency believes a large share of Iran’s most sensitive uranium may be stored in tunnels there. In an Associated Press report carried by PBS NewsHour, IAEA figures put Iran’s uranium enriched up to 60% at 440.9 kilograms, or about 972 pounds. That is below weapons-grade purity, but close enough to remain at the center of the crisis.
The same AP/PBS report said IAEA Director General Rafael Grossi believed roughly 200 kilograms, or about 440 pounds, of highly enriched uranium was stored in tunnels outside Isfahan, while additional quantities may be held at Natanz and Fordo. Inspectors have not been able to fully verify the material since the 2025 strikes disrupted access.
A deal still has moving parts
Reuters reported Friday, as cited by the Jerusalem Post, that the emerging U.S.-Iran framework would include dismantling parts of Iran’s nuclear program and allowing the United States to collect enriched uranium. But the new tunnel report points to the practical question still hanging over the talks: how any removal, destruction, or verification would actually work on the ground.
Scott Roecker, a former head of the National Nuclear Security Administration’s Office of Nuclear Material Removal, told CNN that such fortifications could let Iran claim some uranium is inaccessible. That would matter because the credibility of any deal depends on more than signatures. It depends on whether inspectors can confirm the stockpile and prevent hidden access later.
For now, the claim remains a reported intelligence assessment, not a confirmed public inspection finding. But it is a genuinely new complication in the Iran crisis: even if negotiators agree on Sunday, the hardest part may be proving what is still inside the mountain.
Sources: Jerusalem Post, i24NEWS, PBS NewsHour/Associated Press, Reuters reporting cited by Jerusalem Post.