US President Donald Trump has vowed “serious retaliation” against the Daesh group after an ambush in central Syria killed two US service members and a civilian interpreter, US officials said.

The attack, which took place on Saturday during a joint US-Syrian patrol, also wounded three US troops and at least two Syrian soldiers.

It was the first assault to cause US casualties since the fall of former Syrian president Bashar Al Assad a year ago.

In a social media post, Trump said he had been briefed on the incident and confirmed that the injured Americans were in stable condition.

He warned that those responsible would face severe consequences, calling the assault a Daesh attack in a volatile area of Syria.

US Defence Secretary Pete Hegseth echoed the warning, saying anyone who targets American forces “will be hunted down and killed”.

The US ambassador to Turkiye, Tom Barrack, described the incident as a “cowardly terrorist ambush” and said Syrian troops were also wounded.

He reaffirmed Washington’s commitment to eliminating Daesh remnants in coordination with Syrian authorities.

Details surrounding the attack remain under investigation. The US military said it would withhold the identities of the deceased service members until their families are notified.

Syrian officials said the shooting occurred during a joint patrol near Palmyra.

While some local officials suggested the attacker may have been linked to Syrian security forces, the Interior Ministry said the individual did not hold a leadership role and had previously been flagged for possible extremist views.

US helicopters evacuated the wounded to the Al Tanf base near the Iraqi border, Syrian state media reported.

Traffic on a nearby highway was briefly halted as military aircraft patrolled the area.

The US has about 2,000 troops deployed in Syria as part of ongoing operations against the Daesh group.

Although the group lost its territorial stronghold in 2018, it continues to carry out sporadic attacks across the country.