The family of journalist Austin Tice, missing in Syria since mid-2012, said Thursday they believe he is alive as they stepped up a campaign to win his release.
They unveiled a campaign that will feature digital #FreeAustinTice banners on hundreds of websites of major media groups later this month.
"After almost two and a half years, we feel like we need to let everybody know our son is missing and can you please help us get him home," said Debra Tice, who appeared with husband Marc Tice at a news conference at the National Press Club organized by the media rights group Reporters Without Borders.
Tice, 33, abducted near Damascus on August 14, 2012, is not believed to be held by the Islamic State group which has claimed killing Japanese journalist Kenji Goto last month and American James Foley last year, according to Reporters Without Borders.
Marc Tice said the circumstances of his son's captivity "are still to a large degree a mystery to us" but that the information suggests he is held by "a Syrian entity of one type or other."
The media campaign aims to raise awareness about Tice's captivity because "governments, like people respond to encouragement."
Tice's parents were in Washington to participate in a White House-ordered review of policies to help families of Americans who are taken hostage overseas.
"We were very gratified when President (Barack) Obama directed a review of US hostage policy... and we are pleased to have an opportunity to participate in the review," Marc Tice said.
He said the family was pressing for the government to establish "a single point of contact" for the loved ones of captives.
His wife said she found it "appalling" that "there is no agency or entity committed to the single objective of the safe return of the hostages."
In an opinion piece in the Washington Post, the parents urged the US administration "to better communicate with the families of the missing and kidnapped journalists" and said the loved ones should be able to streamline the process of security clearances.
Tice, a freelance journalist working for McClatchy News, the Washington Post, CBS and others, has been honored with the George Polk Award for War Reporting and the McClatchy President's Award. He has also worked for AFP, the BBC and Associated Press.
After his abduction, an Internet video surfaced which appeared to show him, blindfolded.
US officials said at the time they were not able to verify the video but believed Tice had been was likely held by the regime of Syrian leader Bashar al-Assad.
Syria is the most dangerous country for working journalists, according to Reporters Without Borders, which has documented hundreds of cases of reporters arrested, kidnapped or killed in the country.