(NewsNation) — Iran has warned its military has a free hand to attack U.S. targets after American B-2 bombers hit three Iranian nuclear facilities over the weekend.

The strikes put U.S. military bases in the Middle East in Tehran’s crosshairs.

Iran has already fired missiles at the U.S. Al Udeid Air Base in Qatar on Monday. Those missiles were intercepted and there were no reported casualties, a defense official told NewsNation.

The Trump administration has assured this is not a boots-on-the-ground operation, but military commanders were making preparations Monday ahead of a response from Iran.

Pentagon sources confirmed that bases in Qatar, Kuwait and Iraq are among the most vulnerable to a counterattack because they’re well within range of Iran’s rockets, drones and short-range missiles.

The Al Udeid Air Base in Qatar is a major hub for U.S. Central Command and a prime target.

Defense Secretary Pete Hegseth warned attacks against American bases would be a mistake.

“The United States does not seek war, but let me be clear — we will act swiftly and decisively when our people, our partners or our interests are threatened,” Hegseth said. “Iran should listen to the president of the United States and know that he means it. Every word.”

The U.S. has surged carrier strike groups, including the USS Nimitz and USS Carl Vinson, and has begun voluntary military dependent evacuations.

There are currently more than 40,000 U.S. troops stationed in the region — and that number could grow.