President Joe Biden said Sunday that the U.S. government believes missing American journalist Austin Tice, who disappeared 12 years ago near the Syrian capital, is alive and that Washington is committed to bringing him home after Bashar Assad's ouster from power in Damascus.

"We think we can get him back," Biden told reporters at the White House, while acknowledging that "we have no direct evidence" of his status. "Assad should be held accountable."

Biden said officials must still identify exactly where Tice is after his disappearance in August 2012 at a checkpoint in a contested area west of Damascus.

"We've remained committed to returning him to his family," he said.

Tice, who is from Houston and whose work had been published by The Washington Post, McClatchy newspapers and other outlets.

A video released weeks after Tice went missing showed him blindfolded and held by armed men and saying, "Oh, Jesus." He has not been heard from since. Syria has publicly denied that it was holding him.

The United States has no new evidence that Tice is alive, but continues to operate under the assumption he is alive, according to a U.S. official. The official, who was not authorized to comment publicly and spoke on condition of anonymity, said the U.S. will continue to work to identify where he is and to try to bring him home.

His mother, Debra, said at a news conference Friday in Washington that the family had information from a "significant source," whom she did not identify, establishing that her son was alive.

"He is being cared for and he is well — we do know that," she said.

The Tice family met this past week with officials at the State Department and the White House.

"To everyone in Syria that hears this, please remind people that we're waiting for Austin," Debra Tice said in comments that hostage advocacy groups spread on social media Sunday. "We know that when he comes out, he's going to be fairly dazed & he's going to need lots of care & direction. Direct him to his family please!"