(Adds comments by parents, U.S. official, Rice, McCain)
* Freed soldier arrives at U.S. military hospital in Germany
* Hagel says U.S. did not negotiate with terrorists
* Parents say Bergdahl will need time to decompress
* Qatar acted as intermediary in negotiations
* Taliban five arrive in Qatar, families flown from Afghanistan
By Warren Strobel
WASHINGTON, June 1 (Reuters) - The sole American prisoner of war held in Afghanistan was flown to a U.S. military hospital in Germany on Sunday after being freed in a swap deal for five Taliban militants who were released from the Guantanamo Bay prison in Cuba.
Army Sergeant Bowe Bergdahl had been held for nearly five years and his release, following years of on-off negotiations, suddenly became possible after harder-line factions of the Afghan Taliban shifted course and agreed to back it, U.S. officials said.
U.S. Defense Secretary Chuck Hagel said he hoped the exchange might lead to breakthroughs in reconciliation with the militants and rejected accusations from some Republicans it resulted from negotiations with terrorists, saying the swap had been worked out by the government of Qatar.
"We didn't negotiate with terrorists," Hagel said in an interview on NBC's "Meet the Press". "As I said and explained before, Sergeant Bergdahl was a prisoner of war. That's a normal process in getting your prisoners back."
Bergdahl, 28, was handed over at about 6 p.m. local time on Saturday to U.S. forces who had flown in by helicopter. The Afghan Taliban said they had released Bergdahl near the border with Pakistan in eastern Afghanistan.
He arrived at Landstuhl Regional Medical Center in Germany on Sunday. After receiving care Bergdahl would be transferred to another military medical facility in San Antonio, Texas, U.S. defense officials said, without giving a date for his return to the United States.
His parents, appearing at a news conference in Boise, Idaho, were clearly aware of the long task ahead as Bergdahl adapts to being free, saying he needed time to decompress and his recovery was a "work in progress."
Bob and Jani Bergdahl said they had not yet spoken to their son. They began the news conference with an open message to him, saying how much they loved him and admired his resilience through the long years of captivity.
Bergdahl, from Idaho, was the only known missing U.S. soldier in the Afghan war that began soon after the Sept. 11, 2001 attacks on the United States to force the Taliban - accused of sheltering al Qaeda militants - from power.
He was captured in unknown circumstances in eastern Afghanistan on June 30, 2009, about two months after arriving in the country.
Many U.S. government officials believe Bergdahl was captured after walking away from his unit in violation of U.S. military regulations. But a U.S. official has strongly suggested that Bergdahl was unlikely to be disciplined.
"Our mission now is getting Sergeant Bergdahl healthy and back to his parents," the official said.
U.S. President Barack Obama hailed the release in an appearance with Bergdahl's parents on Saturday in the White House Rose Garden, saying that "while Bowe was gone, he was never forgotten".
In exchange for Bergdahl's freedom, the U.S. released five Taliban detainees from Guantanamo. A senior Gulf source confirmed they had arrived on Sunday in Doha, capital of Qatar, the Gulf emirate that acted as intermediary in the negotiations.
They would not be permitted to leave Qatar for a year, the source said, adding that their families had been flown from Afghanistan.
Qatari Foreign Minister Khaled al-Attiyah said Qatar got involved in the case because it was a "humanitarian cause".
U.S. officials referred to the release of the Taliban detainees as a transfer and said the restrictions placed on them included monitoring of their activities.
Those assurances were greeted with scepticism by U.S. Republicans and some Afghan officials, who voiced concerns that the men, described as senior Taliban figures, would rejoin the insurgency against the government in Kabul.
"They will be very dangerous people, because they have connections with regional and international terror organizations around the world," a senior Afghan intelligence official said.
That view was echoed on the streets of Kabul. "It will strengthen the insurgency," said Sayed Najibullah, a tailor. "President Obama showed that his soldier's life was more important than a country's national interest."
There was no immediate comment from the government of Afghan President Hamid Karzai. Hagel said Karzai was not told in advance of the prisoner exchange.
In Washington some Republicans suggested the administration had bypassed a requirement to notify Congress about a prisoner swap that amounted to a negotiation with terrorists. Republican Senator Ted Cruz of Texas called it a "dangerous price" to pay.
"Have we just put a price on other U.S. soldiers? What does this tell terrorists, that if you capture a U.S. soldier, you can trade that soldier for five terrorists we've gone after," Cruz said on the ABC news program "This Week."
Republican Representative Adam Kinzinger of Illinois said on "Meet the Press": "The release of five mid- to high-level Taliban is shocking to me, especially without coming to Congress. It says in the law you have to notify Congress."
But Obama's national security adviser, Susan Rice, said the administration was concerned about Bergdahl's health and upheld a "sacred obligation" to return soldiers from the battlefield.
"We had reason to be concerned that this was an urgent and an acute situation, that his life could have been at risk," Rice said on "This Week." "We did not have 30 days to wait. And had we waited and lost him, I don't think anybody would have forgiven the United States government."
Republican Senator John McCain, a former prisoner of war and Vietnam War veteran, said there were legitimate questions to be asked about the conditions under which the Taliban prisoners were released.
"These are the hardest of the hard core. These are the highest high-risk people. Others that we have released have gone back into the fight," he said on CBS's "Face the Nation." "That's been documented. So it's disturbing to me that the Taliban are the ones that named the people to be released."
Bergdahl was released days after Obama outlined a plan on Tuesday to withdraw all but 9,800 American troops from Afghanistan by the end of the year and the remainder by 2016, ending more than a decade of U.S. military engagement. (Additional reporting by Mirwais Harooni and Jessica Donati in Kabul, David Brunnstrom in Bagram, Amena Bakr in Doha and Missy Ryan, David Morgan, Phil Stewart and Bill Trott in Washington; Writing by Alex Richardson and Jim Loney; Editing by Jeremy Laurence, Lynne O'Donnell and Frances Kerry)