US diplomats, paying the first visit to Damascus since Islamist-led rebels toppled strongman Bashar al-Assad earlier this month, said they told the new Islamist-led authorities of their priority of finding Tice and other missing Americans.
"We feel it's our duty as the US government to press on until we know with certainty what happened to him, where he is and to bring him home," said Roger Carstens, the US pointman on hostages.
He said that he worked Friday with the new Syrian leadership to search a location where Tice could have been held.
"There are other locations that need to be searched in the coming days, weeks and months, and we'll be working with the interim authorities," Carstens told reporters after the trip.
Tice was working for Agence France-Presse, McClatchy News, The Washington Post, CBS and other media outlets when he was detained at a checkpoint in August 2012.
Carstens said that US teams were not yet authorized to operate in Syria but that he has reached out to non-governmental groups as well as journalists for assistance.
"The bottom line is that over 12 years, we've been able to pinpoint about six facilities that we believe have a high possibility of having had Austin Tice at one point or another," he said.
Carstens said up to three more sites of interests have been added recently and that he hoped for thorough searches of all of them.
Tice's mother Debra said earlier this month that she had information that her son was alive.
Carstens said that the United States was also seeking information about other Americans including Majd Kamalmaz, a Syrian-American psychotherapist believed to have died after being detained under the Assad government in 2017.