New Activity Detected at Iran’s Deeply Buried Nuclear Site as Trump Warns Tehran Not to ‘Get Cute’

New satellite images indicate Iran has reinforced defenses around tunnel entrances at Pickaxe Mountain, a deeply buried nuclear-linked facility that President Donald Trump has repeatedly warned could be targeted. The developments emerged as Russia and China on Thursday vetoed a U.S.-backed Security Council resolution intended to maintain international oversight of sanctions against Tehran.

In a report issued Thursday, the Institute for Science and International Security said imagery captured Sept. 11 showed earthen roadblocks still blocking routes to the western tunnel portals at Pickaxe Mountain, near Iran’s Natanz nuclear complex. The continued limits on access support the institute’s view that the site is not being used for routine operations, though it assessed that important equipment or materials may still be stored inside.

The analysis also found new soil deposits over a western tunnel portal and a nearby group of entrances initially constructed in 2007. According to the institute, the added earth deepens protection around the entrances and further fortifies them against potential airstrikes.

The latest findings were released a week after Trump delivered his most recent warning about Pickaxe Mountain.

“We notice there’s a little activity at Pickaxe,” Trump told reporters last week. “I would advise Iran not to get cute because we will have to hit them very hard.”

Trump has repeatedly suggested the United States could attack the site. During a July 28 appearance on “Fox & Friends,” highlighted by the White House, Trump said the U.S. was closely watching Pickaxe and knew “exactly what’s going on.” He added that Washington could “take out Pickaxe” if diplomatic efforts failed.

Located about two kilometers from Natanz, Pickaxe Mountain has several tunnel entrances leading to a deeply buried underground complex. Work began in 2020 after sabotage damaged an advanced centrifuge assembly facility at Natanz. Iranian authorities later said they were building a replacement underground site for advanced centrifuge production. Analysts believe sections of the facility could be buried at least 100 meters below the mountain’s surface. Iran has maintained that no nuclear activity is taking place there.

Behnam Ben Taleblu, the senior director of the Iran program at the Foundation for Defense of Democracies, told News Media that some analysts believe the window for a relatively straightforward strike on Pickaxe Mountain may already have closed.

“The window to strike Pickaxe Mountain, according to some, has already expired because the regime has dug an underground nuclear facility several times deeper than Fordow,” Ben Taleblu said. But he argued that Washington retains military options even if destroying the underground complex itself proves difficult.

“Washington can do what it’s traditionally been able to do with sites that are underground, hardened and fortified, and that’s to bury their entrances and raise the political cost to the Islamic Republic of being able to dig out,” he said.

“While there may not be the perfect munition just yet, Uncle Sam always has a bigger bomb,” Ben Taleblu added. “And in the meantime, what they can do is show that they mean business by burying the entrances.”

The Pickaxe findings came alongside signs of reconstruction at another sensitive Iranian facility.

In a separate report Thursday, the institute said Iran was “rapidly moving forward” with reconstruction of Taleghan 2 at the Parchin military complex southeast of Tehran. Vantor Technologies satellite imagery from Sept. 13 shows Iran erected a tarp over the destroyed hardened facility, obscuring work underneath from satellite or aerial observation, while dump trucks, bulldozers, concrete equipment and cranes were active around the site.

The institute said Iran also built new concrete reinforcement that could provide additional protection against aerial attack. Taleghan 2 was struck by Israel in October 2024 and again in March 2026 after Iran had rebuilt and hardened the facility. The institute said significant questions remain about Tehran’s plans for the site.

The military developments unfolded alongside a separate confrontation over Iran at the United Nations.

Russia and China on Thursday vetoed a U.S.-authored Security Council resolution that would have extended for another year, until September 2027, the mandate of the Panel of Experts supporting the 1737 Iran Sanctions Committee. The measure received 11 votes in favor, while Pakistan and Somalia abstained.

The panel investigates alleged sanctions violations and reports on implementation. The dispute reflects a deeper split over whether UN sanctions suspended under the 2015 nuclear agreement were legally restored through the “snapback” mechanism. Most Council members maintain that the sanctions and related monitoring structures were revived, while Russia and China reject the legal and procedural validity of that position.

A day before the vote, U.S. Ambassador to the U.N. Mike Waltz told reporters in New York that Washington considers the sanctions legally restored.

“The snapback sanctions… occurred, the United States and this U.N. Security Council followed appropriate procedures for that to occur,” Waltz said Wednesday at a news conference attended by News Media. “Those sanctions are in place and we expect those who are a party to fully enforce those sanctions.”

Waltz said the expert panel is important because sanctioned companies and individuals can attempt to evade restrictions by changing names and corporate structures.

“The president has been clear, and the world community has been clear with resolution after resolution, that the Iranian regime cannot have a nuclear weapon,” Waltz said.

Thursday also brought fresh U.N. scrutiny of both Washington and Tehran. An independent U.N. fact-finding mission said it had reasonable grounds to believe two U.S. strikes on civilian sites in Iran in February constituted war crimes, while separately concluding that Iranian authorities committed crimes against humanity during their crackdown on anti-government protests. The mission is investigative rather than judicial, and its findings do not themselves constitute criminal judgments.

News Media reached out to the Iran U.N. mission for comments but didn’t receive them in time for publication.