U.S. President Donald Trump has repeatedly issued threats to bomb an under-construction Iranian nuclear site buried deep under a mountain as the two nations exchange blows over the Strait of Hormuz. The site, known as Kuh-e Kolang Gaz La, or “Pickaxe Mountain,” lies on the south side of Iran’s Natanz nuclear enrichment site.
Trump told journalists in the Oval Office on Tuesday that the U.S. would be targeting the area “pretty soon” and that “there’s not a thing they can do about it.” He acknowledged the possibility that Iran may have moved centrifuges there, potentially at a depth that would challenge even the most-powerful bombs in America’s arsenal.
The new project at Pickaxe Mountain is being constructed next to Natanz, located about 225 kilometers (140 miles) south of Tehran. Natanz, a facility with both above- and underground components, has been a focal point of international concern since its existence became known two decades ago. Repeated sabotage attacks on Natanz, including one likely carried out by Israel that destroyed a manufacturing site for centrifuges, prompted Iranian officials to begin work on the Pickaxe Mountain site.
Protected by anti-aircraft batteries, fencing, and Iran’s paramilitary Revolutionary Guard, the facility covers 2.7 square kilometers (1 square mile) in the country’s arid Central Plateau and has multiple entrances visible from satellite images. In 2023, analysis from experts at the James Martin Center for Nonproliferation Studies suggested Iran was likely building a facility at a depth of between 80 meters (260 feet) and 100 meters (328 feet). Digging has continued since then, with some experts suggesting it could be even deeper.
Experts believe the scale of the construction indicates Iran will likely use the underground facility for uranium enrichment and to build centrifuges. Centrifuges are tube-shaped devices used to rapidly spin uranium gas to enrich it, and additional cascades would allow Iran to quickly enrich uranium under the mountain's protection.
The U.S. developed the GBU-57 bomb, capable of penetrating at least 60 meters (200 feet) of earth before detonating, in response to such underground facilities. U.S. officials have reportedly discussed using two such bombs in succession, though it remains unclear if this would damage a facility as deep as the one at Pickaxe Mountain.
During a press conference, Trump initially sought to downplay Pickaxe Mountain by focusing on Iran’s stockpile of highly enriched uranium. Iran had enriched uranium up to nearly weapons-grade levels of 60% before the 2025 strikes. It is not known to have restarted enrichment since then, and its stockpile is believed to remain at the bombed enrichment sites.
“We follow the material, that’s where the action is,” Trump told journalists. However, he reiterated that Pickaxe Mountain was a potential target for American bombers amidst ongoing attacks between Iran and the U.S. “Normally I wouldn’t say that,” Trump added. “If I thought they could do something about it, I would never say that, but we’ll be hitting that area pretty soon. And very heavily.”
Iran has stated that areas around its only nuclear power plant at Bushehr have come under attack during the war, though the Russian-run reactor sustained no damage. Tehran also reported that the U.S. attacked the cleared area where it plans to build the Darkhovin nuclear plant, although the U.N.'s International Atomic Energy Agency (IAEA) confirmed no atomic material was present during their last inspection.
The United Arab Emirates' sole nuclear power plant at Barakah, a four-reactor facility, has also been targeted during the war. Iran has since warned of unspecified “required actions” in response to the Darkhovin attack.
In 2025, the U.S. bombed Iran’s nuclear sites at Fordo, Isfahan, and Natanz, all of which had conducted uranium enrichment. Both Israel and the U.S. stated at the time of the 2025 war and the recent Iran war that their aim was to prevent Iran from developing nuclear weapons. Iran has consistently maintained its program is peaceful, and the IAEA and Western nations do not believe it has had an active military nuclear program since 2003. Israel is widely believed to be the Middle East’s only nuclear-armed state.
Despite past declarations, Iranian officials have increasingly threatened to pursue an atomic bomb. The late Iranian Supreme Leader Ayatollah Ali Khamenei, who died on Feb. 28, 2025, in the war's opening moments, had issued a verbal fatwa against nuclear weapons. However, his son, Iran’s new Supreme Leader Mojtaba Khamenei, has not publicly addressed his stance on atomic bombs.
Developing a usable nuclear weapon would require Iran to enrich uranium to 90% purity, build a bomb, and then likely miniaturize it for ballistic missile delivery. This process is estimated to take months or years and would carry significant risks of detection by Israeli or U.S. intelligence.
