President Donald Trump is sending a blunt message to Iran after U.S. intelligence detected new activity around the deeply fortified Pickaxe Mountain nuclear complex: Washington is watching, and Tehran should not mistake surveillance for weakness.
“We notice there’s a little activity at Pickaxe,” Trump said Wednesday night at the Republican National Convention in Texas. “I would advise Iran not to get cute, because we will have to hit them very hard.”
The warning marks a notable change from July, when Trump said the United States was watching the underground facility closely but had seen “no activity” there. Now, the president says something has changed—and he is making sure Iran knows that Washington has noticed.
Trump had already warned last week that the United States could strike Pickaxe Mountain “very soon” if Iran attempted to use the facility to rebuild the nuclear program damaged by previous U.S. and Israeli attacks.
“We know everybody that’s moving at Pickaxe. We know everybody that’s moving everywhere all over Iran,” Trump told reporters in the Oval Office last Friday. “And if anything goes bad, we hit them. We hit them hard.”
That is a very different posture from the ambiguity that often surrounds American warnings. Trump is putting Tehran on notice that the United States is monitoring the site and is prepared to act if Iran crosses the line.
And now the International Atomic Energy Agency is reporting signs of movement of its own.
IAEA Director General Rafael Grossi said Thursday that the U.N. nuclear watchdog had observed indications of activity around the site.
“There are some indications that there is movement around this construction site,” Grossi told Bloomberg TV.
But Grossi also cautioned that the agency does not have enough information to determine exactly what is happening.
“We don’t have any concrete information as to activities that may be taking place there,” he said.
That distinction matters. The IAEA has never inspected the heavily fortified tunnel complex and is relying on remote imagery. Movement around the facility does not, by itself, prove that Iran is conducting nuclear work there.
Still, Pickaxe Mountain is not an ordinary construction project.
According to Grossi, Iran began developing the complex after a 2020 attack severely damaged a centrifuge assembly facility at the nearby Natanz nuclear complex. Iranian officials subsequently indicated that sensitive nuclear infrastructure would be moved underground and protected inside a mountain.
“They said at the time, ‘We are going to put everything in tunnels, inside a mountain,’” Grossi recalled. “This was going to be impermeable and protected from attacks.”
That makes the renewed activity especially significant.
A satellite imagery analysis released Wednesday by the Center for Strategic and International Studies found a “clear surge in construction activity” at Pickaxe Mountain this year, along with more road activity than at any previous point in the site's history.
None of that proves Iran is rebuilding a nuclear weapons capability at the facility. But it does explain why the site is receiving renewed scrutiny—and why Trump is warning Tehran before the situation gets further out of control.
The president's message is simple: America is watching.
Iran can continue testing the limits, moving equipment and personnel, and betting that the United States will hesitate. Or it can take Trump's warning seriously.
“Don’t get cute” may sound casual. Coming from a president who has already demonstrated a willingness to use force against Iran's nuclear infrastructure, it is anything but.
For Tehran, the choice may be whether it wants to discover just how serious Trump is.
