Feb. 25 (UPI) -- The U.S. military conducted airstrikes targeting Iran-backed military groups in eastern Syria on Thursday evening, the Pentagon said, stating it was in response to a deadly rocket attack against U.S. and coalition forces in Iraq last week.
The assault was directed by President Joe Biden, Defense Department press secretary John Kirby said in a statement, making it the first disclosed military operation conducted under the new White House.
Kirby said facilities located at an unnamed border control point used by Kait'ib Hezbollah and Kait'ib Sayyid al-Shuhada, among other Iran-backed groups, were destroyed in the attack.
"These strikes were authorized in response to recent attacks against American and coalition personnel in Iraq, and to ongoing threats to those personnel," Kirby said. "The operation sends an unambiguous message: President Biden will act to protect American and coalition personnel."
The move was also pursued with "aims to de-escalate the overall situation in both eastern Syria and Iraq," he said.
"We know what we hit. We're confident that the target was being used by the same Shia militia that conducted the strikes," he said, referring to a Feb. 15 rocket barrage on a U.S. base at the Erbil airport complex in northern Iraq.
More than a dozen rockets last week were fired at the base near the southeastern Syrian border, killing a contractor and injuring eight others. Four American contractors and a U.S. service member were among those injured in the shelling.
The little-known group Awliya al-Dam, or the Guardians of the Blood, claimed credit for the attack but U.S. officials had repeatedly stated they were working on attribution. They vowed to hold those responsible to account and said Iran is responsible for the acts of its proxies.
Austin told reporters while returning to Washington, D.C., from a California trip that he had recommended the airstrike to Biden, stating the Iraq investigation into the Feb. 15 attack "was very helpful to us in refining the target."
State Department spokesman Ned Price told reporters during a regular press briefing earlier this week that Iranian-made and -supplied rockets have been used in many such attacks but wouldn't say if rockets from Tehran were involved in the Erbil attack, stating they will await the conclusions of Iraq's investigation before attributing blame.
"We will respond in a way that's calculated, on our timetable and using a mix of tools seen and unseen," she said. "What we will not do -- and what we've seen in the past -- is lash out and risk an escalation that plays into the hands of Iran by further destabilizing Iraq."
Michael McCaul, the lead Republican of the House foreign affairs committee, commended the Biden administration for following through on the attack.
"Responses like this are a necessary deterrent and remind Iran, its proxies and our adversaries around the world that attacks on U.S. interests will not be tolerated," he said in a statement.
The extent of the damage or the number of casualties from the Thursday airstrike were unknown.