Two U.S. Army soldiers and a civilian U.S. interpreter were killed Saturday in an attack in Palmyra, Syria, the Pentagon said.

Two American soldiers were killed Saturday after an alleged member of the Islamic State (IS) group opened fire on a US-Syrian joint patrol, AFP cited officials as saying.

In a post on his Truth Social platform, U.S. President Donald Trump vowed "very serious retaliation," mourning the loss of "three great patriots".