Two American troops and an interpreter were killed in central Syria on Saturday after an alleged member of the Daesh group opened fire on a joint US-Syrian patrol, officials said.
US Central Command (Centcom) announced the deaths on X after Syria's state media earlier reported that an attack in the city of Palmyra had wounded American and Syrian troops.
An ambush by a lone Daesh gunman resulted in the deaths and injuries to three additional troops, said Centcom, which oversees the US military in the Middle East.
"The gunman was engaged and killed," it said.
Pentagon spokesman Sean Parnell said the attack occurred as the soldiers "were conducting a key leader engagement" in support of counterterrorism operations, while US envoy to Syria Tom Barrack said the ambush targeted "a joint US-Syrian government patrol."
"The savage who perpetrated this attack was killed by partner forces," US Defence Secretary Pete Hegseth wrote on X.
Parnell said the identities of the deceased troops would be withheld until after their families were notified.
President Donald Trump said that the US would retaliate after two US troops and a civilian interpreter were killed in central Syria by an alleged Daesh militant.
"We will retaliate," Trump told reporters outside the White House, adding just afterwards on his Truth Social platform that Syrian President Ahmed al-Sharaa was "extremely angry and disturbed by this attack."
The incident is the first of its kind reported since the ouster of longtime Syrian ruler Bashar al-Assad in December last year.
A Pentagon official, speaking on the condition of anonymity, said the attack "took place in an area where the Syrian President does not have control."
Syrian state news agency SANA, quoting a security source, earlier reported that several US troops and two Syrian service members had been wounded in the attack.
The soldiers were taking part in a "joint field tour" in Palmyra, which was once under the control of the Daesh group, SANA reported.
A Syrian military official who requested anonymity said that the shots were fired "during a meeting between Syrian and American officers" at a Syrian base in Palmyra.
A witness, who asked to remain anonymous, said he heard the shots coming from inside the base.
According to the Syrian Observatory for Human Rights monitor, which has a wide network of sources inside Syria, the meeting came as part of an "American strategy to strengthen its presence and foothold in the Syrian desert".
Helicopters evacuated the wounded to the Al-Tanf base in southern Syria, where American troops are deployed, SANA said.
Last month, during Syrian President Ahmed al-Sharaa's visit to Washington, Damascus formally joined the US-led global coalition against Daesh.
US forces are deployed in Syria's Kurdish-controlled northeast as well as at Al-Tanf near the border with Jordan.
