The U.S. military carried out airstrikes in Syria after an American contractor was killed and five service members wounded when a drone it said was of Iranian origin crashed into a coalition base.

Secretary of Defense Lloyd Austin, speaks during a briefing with Chairman of the Joint Chiefs, Gen. Mark Milley at the Pentagon in Washington on March 15. Andrew Harnik/Associated Press

The targets of the airstrikes, according to Defense Secretary Lloyd Austin, were “facilities used by groups affiliated with Iran’s Islamic Revolutionary Guards Corps,” in comments late Thursday.

The strikes comes as diplomacy intensifies over Syria’s war, which has entered its 12th year and has drawn in Russia, Iran, the U.S. and Turkey.

Traditional U.S. allies in the Middle East like Saudi Arabia and the United Arab Emirates are going their own way in deescalating with Iran and restoring ties with Syrian President Bashar al-Assad. He’s backed by Tehran and Moscow and remains under Western sanctions.

“The airstrikes were conducted in response to today’s attack as well as a series of recent attacks against Coalition forces in Syria by groups affiliated with the IRGC,” Austin said in a Pentagon statement, adding that President Biden had authorized the action.

National Security Council spokesman John Kirby said Friday that Biden had a discussion with his national security team on his way to Ottawa on Thursday and received recommendations on potential response options.

“He made the decision very, very shortly in that discussion to authorize these strikes against these particular targets,” Kirby told CNN.

He added that the U.S. does not seek war with Iran and is not looking for armed conflict but that the Biden administration would do what it must to defend its troops and facilities.

“And if we have to retaliate, like we did yesterday, we’ll do that.”

Three of the wounded military personnel and a second contractor who was wounded were evacuated to medical facilities in Iraq, according to the statement, which did not provide further details, including on how the drone attack unfolded.

There was no immediate reaction from Iran.

General Michael Kurilla, the leader of U.S. Central Command, called the drone assault “another in a series of attacks on our troops and partner forces.”

“Our troops remain in Syria to ensure the enduring defeat of ISIS, which benefits the security and stability of not only Syria, but the entire region,” he said in a statement.

Last August, U.S. helicopters hit Iranian-backed militants in Syria after rockets were fired at bases where Americans were stationed. In June 2021, Biden ordered airstrikes in Syria and Iraq against militias tied to Iran.

His first military action as president, in February 2021, involved raids in eastern Syria on sites connected to Iranian-backed groups following a series of rocket attacks on facilities in Iraq used by the U.S., including one that killed a contractor.

In testimony to Congress on Thursday, Gen. Mark Milley, the chairman of the Joint Chiefs of Staff, said the U.S. had almost 1,000 troops in Syria and that they had occasionally come under attack.

Russia has been pushing for the regional rehabilitation of Assad. Saudi Arabia is in discussions with Damascus to resume consular services between the two countries, according to an unnamed Saudi Foreign Ministry official cited by the state-owned Al-Ekhbariya TV channel.

That comes two weeks after Saudi Arabia accelerated rapprochement with Iran, signing an agreement to restore diplomatic ties with Tehran in a deal brokered by China.

Saudi Foreign Minister Prince Faisal bin Farhan, who previously said that Syria’s isolation from the Arab world was “not workable,” spoke on Wednesday with his Iranian counterpart Hossein Amirabdollahian to discuss plans for an upcoming meeting.