(CNN) The Obama administration has "high confidence" that missing American journalist Austin Tice is alive in Syria, Sen. John Cornyn said Friday.
Freelance journalist Tice disappeared while reporting near the Syrian capital of Damascus in August, 2012.Texas Republican Cornyn, the second-ranking GOP leader in the Senate, said he had been briefed on the latest situation by White House hostage envoy James O'Brien.
O'Brien was able to deliver "positive, yet cautious news" about Tice, Cornyn said. O'Brien said that there is "high confidence that Austin is alive in Syria."
Five weeks after Tice disappeared, a 43-second video emerged online that showed him in the captivity of what his family describe as an "unusual group of apparent jihadists." There has been no public word on what has happened to him since.
Tice, a Texas native, is a veteran of the US Marine Corps and was a law student at Georgetown.
"Today's news should remind us that we cannot give up until we bring Austin Tice home," Cornyn said.
"I renew once again my call for his immediate release by his captors, and I strongly urge the current and future administration to continue to utilize all possible means to secure his safe return."
Tice's parents met with Cornyn last week in Austin, Texas. CNN has not been able to reach them since Cornyn's comments.
"While this is certainly positive news, I can't help but think of his parents and what they have had to go through these last four years," Cornyn said.
Tice is the only American journalist still held captive in Syria, according to Reporters Without Borders -- which has launched the online awareness campaign #FreeAustinTice. To date nearly 150,000 people have signed an online petition.