The US military never conducted an independent investigation into a 2019 bombing on the last bastion of the Daesh terror group, despite concerns about a secretive commando force which may have committed war crimes.
UN war crimes investigators have urged the United States to carry out thorough probes into civilian casualties caused by US air strikes in Syria to ensure that those responsible for any violations are held to account.
The UN Commission of Inquiry on Wednesday reiterated a "recommendation to the United States and all parties to conduct credible, independent and impartial investigations into incidents entailing civilian casualties in which their forces are implicated".
The panel called on Washington to ensure those responsible for violations are held accountable and to make their findings public.
In November, US Defense Secretary Lloyd Austin ordered a review of a 2019 strike in the Syrian town of Baghuz that caused civilian casualties, the Pentagon said at the time.
The New York Times had reported that the strike killed up to 64 women and children, a possible war crime, during the battle against Daesh.
Sanctions on Syria
The independent experts also called for easing Western sanctions on Syria to mitigate their impact on civilians who are grappling with shortages and "skyrocketing" inflation.
In November last year the The New York Times reported that the casualties occurred in an air strike that came without warning during the last days of the fight against Daesh in the eastern part of the country.
First, a US military drone spotted a crowd and an American F-15E attack jet bombed the civilians, followed by another jet that tracked the crowd and killed most of the survivors, said the Times.