(CNN) The Biden administration has had direct engagements with the Syrian government in an effort to secure the release of detained American Austin Tice, according to a source familiar and a senior administration official.
There have been a number of direct interactions -- none of which took place in Damascus -- but they have thus far yielded no progress, the source familiar said.
The senior administration official confirmed the direct contact, first reported by McClatchy, noting it was one of multiple avenues the administration is pursuing in an effort to free Tice.
This week marks the tenth anniversary of Tice being taken hostage in Syria. President Joe Biden on Wednesday declared that the US government knows "with certainty that he has been held by the Syrian regime."
Although the US has offered to hold senior-level meetings with the regime of Bashar al-Assad to discuss Tice's case, Syrian officials have flatly refused, both in direct and indirect conversations, the source familiar told CNN. The Syrian officials have not offered any explanation for their refusals or any demands or preconditions for such discussions to take place, they added.
"The United States has engaged extensively to try to get Austin home, including directly with Syrian officials and through third parties," the senior administration official said. "Unlike in other situations where Americans are detained abroad, for many months, the Syrian government has not agreed to senior-level meetings to discuss Austin's case, nor has it ever acknowledged holding him."
"We will continue to pursue every avenue for securing Austin's release," the official said.
A State Department official added that the "US government is extensively engaged with Syrian officials to bring Tice home, but Syria has never even acknowledged holding him."
In addition to the direct engagement, the administration has used backchannels, including Lebanese intel chief Abbas Ibrahim. Ibrahim, who has played a role in securing the release of American detainees in the past, traveled to Washington, DC in May of this year.
Ibrahim made the trip at the request of the administration, he told CNN, and met with Special Presidential Envoy for Hostage Affairs Roger Carstens and CIA Director Bill Burns, among others. In the weeks following that visit, Ibrahim said he traveled to Damascus for discussions about Tice and another detained American, Majd Kamalmaz. He told CNN he has conveyed a response from Syria to Washington, but would not get into details given the sensitivity of the matter.
Ibrahim said he is "proud to work on this case," telling CNN, "I believe I'm doing my best to solve this problem."
Tice's parents, Austin and Debra, have called for direct engagement with Damascus to try to secure the release of their son. Debra Tice told CNN's "New Day" Thursday that she appreciated that Biden used Austin's name publicly and said she saw it as "an indication from the President that the United States government is ready to engage with Syria to bring Austin home."
In his statement Wednesday, Biden said his administration has "repeatedly asked the government of Syria to work with us so that we can bring Austin home."
"On the tenth anniversary of his abduction, I am calling on Syria to end this and help us bring him home," the President said, adding that the "Tice family deserves answers, and more importantly, they deserve to be swiftly reunited with Austin."