In 2012, Rolling Stone magazine quoted emails Bergdahl is said to have sent to his parents that suggest he was disillusioned with America's mission in Afghanistan, had lost faith in the U.S. Army and was considering desertion. Bergdahl told his parents he was "ashamed to even be American." The Associated Press could not independently authenticate the emails.
Hagel declined to say whether he believes Bergdahl was attempting to desert the Army or go AWOL when he walked away from his unit and disappeared.
"Our first priority is assuring his well-being and his health and getting him reunited with his family," Hagel said. "Other circumstances that may develop and questions — those will be dealt with later."
A senior U.S. official told The Associated Press that the Army would make the decision on any charges but that the feeling at the moment was that Bergdahl had suffered enough in his ordeal. All the officials who discussed details of Bergdahl's transfer insisted on anonymity because they were not authorized to be identified.
The U.S. has long sought Bergdahl's release, but there was renewed interest in his case as Obama finalized plans to pull nearly all American forces out of Afghanistan by the end of 2016.
Officials said the Taliban signaled to the U.S. in November that they were ready to start fresh talks on the issue of detainees. After the U.S. received proof that Bergdahl was still alive, indirect talks began, with Qatar sending messages back and forth between the two parties.
The five Guantanamo detainees departed the base on a U.S. military aircraft Saturday afternoon. Under the conditions of their release, they will be banned from traveling outside of Qatar for at least one year.
Obama and the emir of Qatar spoke last week about the conditions of the release, which have been codified in a memorandum of understanding between the two countries, officials said.
The detainees were among the most senior Afghans still held at the prison:
—Abdul Haq Wasiq, who served as the Taliban deputy minister of intelligence,
—Mullah Norullah Nori, a senior Taliban commander in the northern city of Mazar-e-Sharif when the Taliban fought U.S. forces in late 2001
—Khairullah Khairkhwa, who served in various Taliban positions including interior minister and had direct ties to Mullah Omar and Osama bin Laden
—Mohammed Nabi, who served as chief of security for the Taliban in Qalat, Afghanistan, and later worked as a radio operator for the Taliban's communications office in Kabul
—Mohammad Fazl, whom Human Rights Watch says could be prosecuted for war crimes for presiding over the mass killing of Shiite Muslims in Afghanistan in 2000 and 2001 as the Taliban sought to consolidate their control over the country.
In a statement on the Taliban website that was translated by the Washington-based SITE Intelligence Group, the Taliban said it "was and has been for a long time attempting to free all the imprisoned Afghan prisoners inside and outside the country, and restoring the right of freedom to them quickly."