At the annual Rolling Thunder rally on the National Mall, Bob Bergdahl promised his son: "You will come home. We will not leave you behind."
Army Sgt. Bowe Bergdahl, 26, of Hailey, Idaho, was taken prisoner in Afghanistan nearly three years ago. He is the subject of a proposed prisoner swap in which the Obama administration would allow the transfer of five Taliban prisoners long held at the U.S. military prison at Guantanamo Bay, Cuba.
Bergdahl said he couldn't be happier with the government's efforts to return his son.
"This is a complicated issue and it's going to demand all aspects of American government. And we need joint cooperation, we need every level, every agency and every dimension of American government to cooperate and pay attention," he said. "We're on a mission to get our son home and we're not going to stop until we accomplish that."
Motorcyclists attending the ceremony wore yellow wristbands with Bergdahl's name and the date he went missing on them. Many also wore the traditional biker gear of leather vests and riding boots, even though temperatures reached the 90s.
Hundreds of thousands of bikers, including military veterans and non-veterans, gathered in the nation's capital this weekend for the Rolling Thunder rally.