WASHINGTON — Nearly five years after his capture by insurgents, Sgt. Bowe Bergdahl climbed into an American helicopter. He took out a pen and wrote on a paper plate, “SF?” — asking the troops who had come to find him in eastern Afghanistan if they were U.S. special operations forces.

Over the roar of the rotors, one of them shouted to Bergdahl: “Yes, we’ve been looking for you for a long time.”

The only American prisoner of the Afghan war, Bergdahl broke down in tears.

The emotional moment was described by a defense official, one of several U.S. officials who detailed Bergdahl’s release Saturday. In exchange for the 28-year-old American, President Barack Obama agreed to release five high-level Afghan detainees from the U.S. prison at Guantanamo Bay, Cuba.

“While Bowe was gone, he was never forgotten,” Obama said in a statement. “The United States of America does not ever leave our men and women in uniform behind.”

Bergdahl’s parents, Bob and Jani, led a tireless campaign to keep their son’s story in the public eye.

Bergdahl, in good condition and able to walk, was handed over to U.S. special operations forces by the Taliban in an area of eastern Afghanistan, near the Pakistani border, U.S. officials said. In a statement on its website, the Taliban put the location on the outskirts of Khost province.

The handover followed indirect negotiations between the U.S. and the Taliban, with the government of Qatar serving as the go-between.

Some U.S. officials said this type of exchange is somewhat unprecedented during the last 13 years of war in Iraq and Afghanistan. In weighing the swap, U.S. officials decided that it could help further the effort to reach reconciliation with the Taliban.