Two US Army soldiers and a civilian translator were killed in an attack in Syria on Saturday, according to the Department of Defense.
"Three others were injured in the attack," said Sean Parnell, the Pentagon's chief spokesman.
"The attack occurred while the soldiers were conducting a key engagement with leaders. Their mission was in support of ongoing anti-ISIS/counterterrorism operations in the region," Parnell said, adding that the names of those killed would be withheld pending notification of their next of kin.
Defense Secretary Pete Hegseth said the attacker was killed by partner forces.
"Let them know, if you target Americans — anywhere in the world — you will spend the rest of your short and anxious lives knowing that the United States will track you down, find you, and kill you mercilessly," he said.
The US soldiers were shot during a joint patrol with Syrian forces in central Syria, according to the official national news agency SANA.
Traffic on the highway between Deir Ezzor and Damascus was stopped in connection with the incident.
"American helicopters intervened to evacuate the wounded at al-Tanf base after the shooting incident," SANA reported.
Al-Tanf is a US base in eastern Syria on the border with Iraq. /Telegraph/
