U.S. military on Thursday conducted airstrikes in Syria against facilities that the Pentagon say are used by Iranian-backed militant groups, in response to recent rocket attacks against American forces in the region.

It is the first known military action ordered by U.S. President Joe Biden who took office about a month before.

U.S. President Joe Biden delivers remarks at a virtual Munich Security Conference on Feb. 19, 2021, in the White House in Washington. (Pool/Getty/Kyodo)

"President Biden will act to protect American and coalition personnel. At the same time, we have acted in a deliberate manner that aims to de-escalate the overall situation in both eastern Syria and Iraq," Defense Department Press Secretary John Kirby said in a statement.

The strikes destroyed multiple facilities located at a border control point used by a number of Iranian-backed militant groups, he said.

The Biden administration had expressed its outrage against rocket attacks in Iraq on Feb. 15, which reportedly killed one civilian contractor and injured an American service member and other coalition personnel.