Two U.S. Army soldiers and one U.S. civilian interpreter were killed while three service members were left wounded in an ambush attack on Saturday in Palmyra, Syria, U.S. officials confirmed.

Sean Parnell, the Pentagon spokesperson, confirmed the news on X Saturday morning, saying the two soldiers “were conducting a key leader engagement” and that their mission in the city was “in support of on-going counter-ISIS / counter-terrorism operations in the region.

In a press release, U.S. Central Command said the attack was carried out by a “lone ISIS gunman” who was “engaged and killed.”

President Donald Trump on Saturday said that in light of the attack, which he framed as an assault on both the U.S. and Syria, there will be “serious retaliation.” The president also said the soldiers were killed “in a very dangerous part of Syria, that is not fully controlled by them.”

A Pentagon official said that Saturday’s attack took place in an area where current Syrian President Ahmed al-Sharaa does not have control.

As of April, the U.S. had about 2,000 troops stationed in Syria involved in advisory, training, and counter-ISIS missions.

Secretary of Defense Pete Hegseth confirmed that the person who perpetrated the attack had been killed.

“Let it be known, if you target Americans — anywhere in the world — you will spend the rest of your brief, anxious life knowing the United States will hunt you, find you, and ruthlessly kill you,” Hegseth added in his post on X.

The Kurdish-led and U.S.-backed Syrian Democratic Forces also weighed in on X, saying, “We express our regret for the injury of a number of public security personnel and U.S. soldiers following their exposure to gunfire in the Syrian Badia while performing their duties,” according to a translation of the post from Arabic.

The U.S. first deployed to Syria during the Obama administration as part of the Operation Inherent Resolve coalition to fight ISIS. After ISIS lost almost all territorial control by 2019, the U.S. did not fully withdraw but kept a smaller contingent of troops in the Middle Eastern nation to prevent the group’s resurgence.

In 2024, the longstanding government of former Syrian President Bashar al-Assad fell, and a new transitional Syrian government formed with U.S. encouragement.

Parnell, in his statement, said the soldiers’ names, as well as identifying information about their units, are being withheld for 24 hours after the next of kin notification. He also said an active investigation is underway.