The video footage appears to show US commandos fleeing a Syrian town under a barrage of abuse and insults hurled at them by fighters from the American-backed Free Syrian Army (FSA) rebel group.
The video appears to be the first evidence of US special forces cooperating with Turkish troops in their battle against Islamic State (Isil).
The incident illustrates the complex web of alliances and enmities in Syria, where many of America’s allies are fighting each other and some rebel groups that receive US support still harbour strong anti-American sentiments.
The footage shows a crowd of rebel fighters in the town of al-Rai near the Turkish border, which was captured from Isil by Syrian rebel groups with the backing of Turkey. Turkey, which launched a military incursion into Syria in late August, has been backing the FSA.