RACHEL MARTIN, HOST:

This is a WEEKEND EDITION from NPR News. I'm Rachel Martin. This morning, the only American POW of the Afghan War is a free man. Army sergeant Bowe Bergdahl had spent almost five years held captive by the Taliban. President Obama announced the news of his release in an address yesterday at the White House. Standing beside the president, Bergdahl's parents.

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PRESIDENT BARACK OBAMA: Sergeant Bergdahl has missed birthdays and holidays and the simple moments with families and friends, which all of us take for granted. But while Bowe was gone, he was never forgotten.

MARTIN: But Bergdahl's freedom came at a price. The president announced that in exchange, five high-ranking Taliban leaders were released from Guantanamo Bay into the custody of the government of Qatar. Some Republican law-makers are criticizing the Obama administration for negotiating with the Taliban. President Obama suggested the prisoner exchange could open a new door for potential peace talks with Afghanistan.

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OBAMA: I also want to express gratitude to the Afghan government, which has always supported our efforts to secure Bowe's release. Going forward, the United States will continue to support an Afghan-led process of reconciliation, which could help secure a hard-earned peace within a sovereign and unified Afghanistan.

MARTIN: This morning, U.S. Secretary of Defense Chuck Hagel made an unannounced visit to Bagram Airfield, outside Kabul, where he met with the special operations forces who secured Bergdahl's release. NPR's report Sean Carberry has been tracking the story from Kabul. Her joins me now. Sean, what do we know about Sergeant Bergdahl's whereabouts at this point?

SEAN CARBERRY, BYLINE: At this point, he's now in Germany at the U.S. base there, undergoing medical treatment. And the medical issue seems to be a big part of the reason why this operation happened at this time. Secretary of Defense Hagel said that they intel that Bergdahl's health and safety were in jeopardy. He was released, and he's now being treated and will be reunited with his family once he has judged healthy enough to do so.

MARTIN: What do we know, Sean, about the nature of his captivity and how he was treated all those five years?

CARBERRY: Well, it's generally believed that while he was actually captured by members of the Taliban, he was being held by the Haqqani network in Pakistan. And Haqqanis are affiliated with the Taliban, but they're considered a more hard-core militant group. And they're based in the tribal areas of Pakistan, which is where it's believed that Bergdahl spent most of his time in captivity. Though, when he was released yesterday, he was released in Eastern Afghanistan by members of the Taliban and handed over to U.S. Special Forces.

MARTIN: Sergeant Bergdahl was captured by the Taliban in 2009 on June 30. The nature of his capture, though, is complicated. Can you remind us what the circumstances were?

CARBERRY: Yeah. There are still open questions about this. There are arguments that he was disillusioned. He hadn't been in Afghanistan very long. Had written letters home talking about how disappointed he was with the American effort there. And then, he essentially walked off the base with little more than a bottle of water and a diary. So he effectively deserted, walked off and was captured.

But there are other accounts saying he was lagging behind on a patrol and was grabbed then, other accounts that he was taken after doing guard duty. So it's still unclear, though the consensus does lean towards the explanation that he did voluntarily just walk off and essentially go AWOL.

MARTIN: And Sean, what's been the reaction in Afghanistan so far from the Taliban and Afghan officials?

CARBERRY: Well, the Taliban have praised it. And they've been complimentary of Qatar, which brokered the deal and where the five Taliban will be spending the next year living under a form of house arrest. The Afghan High Peace Council here says, again, this is a victory for the peace process and this sends a message that everyone should continue to invest in peace. Western officials here also say that this is a victory for the Taliban faction at that favors peace talks, and they hope this will lead to continued breakthroughs in the peace process.

MARTIN: NPR's Shawn Carberry in Kabul. Thanks so much, Sean.

CARBERRY: You're welcome, Rachel. Transcript provided by NPR, Copyright NPR.