We hold Bashar al-Assad and his criminal regime accountable for the consequences of Austin’s disappearance and the pain inflicted on his mother — pain, tears and separation," a spokesman told NBC News.

The U.S. is communicating with rebel groups inside Syria amid the search for missing American journalist Austin Tice, State Department spokesperson Matthew Miller said.

U.S. officials are now in Syria and pushing for a peaceful transition after the fall of the Assad regime. It comes as the discovery of an American freed from a Syrian prison raises hopes that other Americans held there could be found,

The parents of Austin Tice spoke out in an interview with ABC News as the U.S. works to uncover their son’s whereabouts after the collapse of the Assad regime in Syria.