HAILEY: Hundreds of supporters rallied on Saturday in the central Idaho, hometown of prisoner-of-war Bowe Bergdahl, to call for the safe return of the US Army sergeant believed to be held captive by Taliban militants in northwestern Pakistan.

The rally, expected to be the largest yet for the only known American prisoner of war tied to the Afghanistan conflict, marks the latest effort by residents of Hailey, a close-knit town of 7,000, to draw attention to Bergdahl's plight and push for his release.

Bergdahl, now 27, was serving with an Alaska-based infantry unit when he disappeared from his base in southern Afghanistan in June 2009 and was taken captive by the Taliban.

Saturday's gathering in Hailey caps a week of renewed hope for Bergdahl's release amid reports of a potential prisoner exchange as part of planned peace talks between the United States and the Taliban.

But the latest bid to end Afghanistan's 12-year-old war appeared to lose momentum late this week after news that the Taliban would open an office in Qatar - a step seen as paving the way for peace talks - drew the fury of Afghan President Hamid Karzai.

As many as 1,000 motorcyclists from US clubs tied to helping the causes of veterans and prisoners-of-war were expected on Saturday afternoon to escort Bergdahl's father, Bob, to a local park, where he and his wife would speak in a rare public appearance.

“Wars are very easy to get into and very difficult to get out of, especially in South Asia,” Bergdahl said in an e-mail to CBS News on Friday. “Diplomacy, diplomacy, diplomacy ... it is long overdue in the region.”

Through a family spokesman, Bob Bergdahl declined an interview with Reuters ahead of the rally.

In a statement earlier this month, Bergdahl said he and his wife had received a letter from their son that gave them hope he is well despite his circumstances.

The trees on Hailey's main street have been decorated with yellow ribbons for four years to show that the town - sandwiched between a world-class trout stream and the towering Sawtooth Mountains - has not forgotten its native son.

“When something happens to one person in our community, it happens to everyone in our community,” said Debbie O'Neill, a Bergdahl family friend who organized Saturday's rally. “None of us will rest until Bowe's safely home.”