The International Atomic Energy Agency, IAEA, has detected signs of activity at Iran’s Pickaxe Mountain complex, a site that Western intelligence agencies have identified as a possible location for storing nuclear material.
IAEA Director General Rafael Grossi told Bloomberg that satellite imagery reviewed by the UN nuclear watchdog showed indications of movement around the site, although the agency does not have sufficient information to determine what activities are currently taking place there.
“There are some indications that there is movement around this construction site,” Grossi said. “We don’t have any concrete information as to activities that may be taking place there.”
The IAEA has not been able to conduct inspections inside the underground facility at Pickaxe Mountain, located near Iran’s Natanz nuclear complex. Instead, the agency has been monitoring developments remotely through imagery.
Grossi said Iranian officials had previously indicated that sensitive nuclear infrastructure would be moved into underground facilities built inside mountains to protect it from potential military attacks.
The situation has become more significant since Israeli and US strikes damaged Iranian nuclear facilities during the 12-day conflict in June 2025.
Iran has subsequently restricted IAEA access to nuclear sites affected by the attacks, leaving the agency unable to independently verify the current condition of Iran’s stockpile of uranium enriched to near weapons-grade levels.
US President Donald Trump has meanwhile warned Tehran against further activity at the site, saying Washington was monitoring developments at Pickaxe Mountain and could take military action.
“We notice there’s a little activity at Pickaxe,” Trump said during a speech at the Republican National Convention, warning Iran that the United States could respond forcefully.
A separate assessment by the Center for Strategic and International Studies (CSIS) also pointed to increased activity at the site.
The Washington-based think tank said its analysis of six years of satellite and other imagery showed a distinct progression in construction activity across five key areas and connecting roads.
According to CSIS, the site appears to have moved from large-scale excavation toward internal construction and continued reinforcement of its external infrastructure.
The group said imagery from 2026 showed the highest level of road activity recorded at Pickaxe Mountain since monitoring of the site began.
It identified increased work around tunnel entrances, improvements to internal roads, reinforcement of access points and the clearing of excavated material as indicators of intensified construction.
IAEA reports construction activity at Iran’s Pickaxe Mountain site