Two members of the U.S.-led coalition in Syria, one American and the other British, were killed in a roadside bomb blast Thursday night, according to U.S. officials. Five others were wounded.
Two U.S. officials speaking anonymously to Reuters said the attack occurred near the city of Manbij in northern Syria.
An earlier statement from the U.S. military did not indicate where the attack occurred, nor did it disclose the names and nationalities of the victims, saying only that they were coalition members.
U.S. military spokesman Colonel Ryan Dillion did not immediately say who was responsible for the attack, but added, "We have our initial assessment and thoughts on that but we won't provide [it] until the investigation is complete."
Britain's Defense Ministry confirmed the second fatality came from within its ranks. A defense spokesman said that the British service member was embedded with U.S. forces at the time of the attack and that the coalition forces were carrying out an operation against the Islamic State group.
The attack near Manbij, a former Islamic State stronghold where U.S. forces are stationed, occurred one day after U.S. President Donald Trump said he would withdraw U.S. forces in the near future.
"We're coming out of Syria, like, very soon. Let the other people take care of it now. Very soon — very soon we're coming out," Trump said in a speech in the Midwestern U.S. state of Ohio, without offering details.
However, a U.S. defense official said the U.S. mission in Syria remains unchanged, and added that U.S. troops are there to defeat IS.
The U.S. has more than 2,000 military personnel in Syria, 60 of whom have been killed since the campaign to destroy IS began in 2014.
There were conflicting reports, meanwhile, about whether the main rebel group in eastern Ghouta near Damascus had agreed with Russia to leave the town of Douma, the largest and last remaining rebel-held town in the area.
"Our position is still clear and firm and it is rejecting forced displacement and demographic change in what remains of eastern Ghouta," said Hamza Birqdar, a spokesman for the Jaish al-Islam rebel group, which controls Douma.
Col. Gen. Sergei Rudskoi of the Russian military's General Staff said earlier it had reached agreement with the rebels in Douma to leave.
Syrian government forces have surrounded Douma, where tens of thousands of civilians live. Thousands of people have been fleeing violence in the eastern Ghouta area to the northwestern Syrian city of Idlib.
The Syrian government's recent military offensive in the area has claimed more than 1,600 civilian lives, according to the Syrian Observatory of Human Rights.
The recapture of Douma would represent a major victory for President Bashar al-Assad, as it would eliminate the last major rebel stronghold in the Damascus area since the war began seven years ago.
VOA National Security Correspondent Jeff Seldin contributed to this report.