No injuries were reported and the damage was still being assessed in and around the U.S. base in Deir Ezzour in eastern Syria, said Army Col. Wayne Marotto, a spokesman for Operation Inherent Resolve.
U.S. troops responded with artillery fire at rocket launching positions, he said.
The attack occurred just before 7:45 p.m. local time. No other information was provided. Pro-Iranian militias claimed they fired the rockets at an American base in response to the airstrikes, The Jerusalem Post reported.
The airstrikes targeted “facilities used by Iran-backed militia groups” near the border between Iraq and Syria, officials said.
“The United States took necessary, appropriate, and deliberate action designed to limit the risk of escalation — but also to send a clear and unambiguous deterrent message,” said Pentagon Press Secretary John Kirby.
Kirby said the U.S. military targeted three operational and weapons storage facilities — two in Syria and one in Iraq. In its release of videos of the strikes by Air Force F-15 and F-16 aircraft, the Pentagon described one target as a coordination center for the shipment and transfer of advanced conventional weapons.
The Pentagon said the facilities were used by Iran-backed militia factions, including Kata’ib Hezbollah and Kata’ib Sayyid al-Shuhada.
“The targets selected were facilities utilized by the network of Iran-backed militia groups responsible for the series of recent attacks against facilities housing U.S. personnel in Iraq,” Pentagon spokeswoman, Navy Cmdr. Jessica McNulty, said Monday. She said those groups have conducted at least five such “one-way” drone attacks since April.
Sunday’s strikes mark the second time the Biden administration launched airstrikes along the Iraq-Syria border region. In February, the U.S. launched airstrikes against facilities in Syria, near the Iraqi border, that it said were used by Iranian-backed militia groups.
The Iraqi military condemned the U.S. airstrikes as a “blatant and unacceptable violation of Iraqi sovereignty and national security” and militia groups called for revenge against the United States.
Iranian foreign ministry spokesman Saeed Khatibzadeh accused Washington of creating instability in the region.
“Definitely, what the U.S. is doing is disrupting the security of the region,” he said on Monday.
Fox News’ Jennifer Griffin and the Associated Press contributed to this report.