Timmerman, 29, had not contacted his family for months after he went on a trip to Eastern Europe. His discovery came in the wake of the overthrow of the Assad regime.

The exchange took place at the remote U.S. base in southeastern Syria known as At Tanf garrison, close to the border with Jordan.

Travis Timmerman, 29, was evacuated from Syria by a U.S. military helicopter, according to a U.S. official who spoke to The Associated Press on condition of anonymity due to the ongoing nature of the operation.