President Donald Trump has issued a fresh warning to Iran after the United States observed renewed activity at Pickaxe Mountain, a heavily fortified underground complex near Iran’s damaged Natanz nuclear enrichment facility.
Speaking Wednesday at a Republican convention, Trump said Washington was closely watching activity at the site and warned Tehran against taking provocative action.
“We notice there’s a little activity at Pickaxe,” Trump said, adding that Iran could face a major U.S. strike if the situation escalates.
New Activity at the Underground Complex
Pickaxe Mountain has become an increasingly important focus in the confrontation over Iran’s nuclear program.
The site contains two deeply buried tunnel complexes near Natanz, making it considerably more difficult to target than conventional above-ground facilities.
A new satellite imagery analysis from the Center for Strategic and International Studies found a significant increase in construction activity at Pickaxe Mountain during 2026.
Researchers observed increased road activity, reinforcement around tunnel entrances, paving and other construction work.
However, the researchers stressed that the available imagery does not prove that Iran is currently enriching uranium inside the facility.
Why Washington Is Watching Pickaxe Mountain
Iran’s nuclear infrastructure has suffered extensive damage during previous military operations, increasing international attention on deeply buried facilities that could potentially be used to protect sensitive equipment.
Pickaxe Mountain has therefore become one of the sites being closely watched by Washington.
Trump has threatened strikes against the facility before, but his latest warning comes as new satellite analysis shows construction activity there has accelerated.
U.S.–Iran Tensions Remain Extremely High
The warning comes during another dangerous period in the U.S.–Iran conflict.
Military confrontations around the Strait of Hormuz have intensified, while disruptions to Middle Eastern energy supplies have pushed Brent crude above $100 per barrel.
Any new U.S. attack on a site connected to Iran’s nuclear program could trigger another round of retaliation and further destabilize global energy markets.
For now, Washington appears to be watching Pickaxe Mountain closely — but Trump’s latest warning makes clear that additional U.S. military action remains on the table.