• Senators unconvinced after being shown 'proof-of-life' video • US president says it was his responsibility to save soldier's life

President Obama is refusing to apologise for his decision to swap the American soldier Bowe Bergdahl for five Taliban fighters, standing firm in the face of a growing firestorm in Washington that his administration is struggling to quell.



Republicans have accused Obama of bypassing Congress and endangering American lives by releasing the fighters, who were being held at Guantánamo Bay. A White House attempt to defuse the row by giving senators a private viewing of a disturbing “proof of life” video the Taliban sent to the US to show that Bergdahl was still alive did little to stem the criticism.



Speaking in Brussels during a press conference with UK prime minister David Cameron on Thursday, Obama showed no sign of giving into the pressure, insisting he had made the right decision and saying he was motivated by his responsibility as commander-in-chief to save the soldier's life.



“I make absolutely no apologies for making sure we get back a young man to his parents and that the American people understand this is somebody’s child and that we don’t condition whether or not we make the effort try to get them back,” he said.



Obama’s remark that the US does not “condition” its efforts to rescue captured military personnel was an implicit swipe at the suggestion now infused in much of the debate in Washington that Bergdahl was somehow undeserving of the prisoner exchange because, prior to his capture, he may have voluntarily left his base after growing disillusionment with the American war effort.



“I am never surprised by controversies that are whipped up in Washington. That is par for the course,” Obama said, repeating his argument that he was abiding by a “basic principle” that the US would not abandon its military personnel.



“We saw an opportunity and we seized it, and I make no apologies for that,” he said.



Wednesday's classified briefing to senators, which gave them an opportunity to see the “proof of life” video showing Bergdahl in poor health, was intended to shed a light on the reason Obama felt compelled to act quickly to secure his release. The previously unseen video had been demanded by the administration in advance of negotiations with the Taliban.

However, Republican and even some Democratic senators emerged from the meeting unconvinced, saying they were sceptical about the arguments behind the exchange and concerned the former Guantánamo detainees would now return to the battlefield.



Exactly how or why Bergdahl left his remote post in Afghanistan remains unknown, but some of the soldier’s former colleagues have said his departure was an act of desertion that put fellow members of his platoon at risk and should now be punished.



Defense secretary Chuck Hagel has said critics should wait for the facts before rushing to judge Bergdahl.



Criticisms of the administration’s handling of the case are manifold and include the bungled announcement of Bergdahl’s release over the weekend, when the White House apparently misread what the political reaction to his release would be.



Obama hailed Bergdahl’s release in the White House Rose Garden, flanked by the soldier’s parents, Jani and Bob, from Idaho. Bob Bergdahl’s criticism of US military policy, including in a video interview with the Guardian, helped turn hawks against the family, who have remained silent since their appearance at the White House.



Obama on Thursday defended the Rose Garden press conference. “I think it was important for people to understand that this is not some abstraction, this is not a political football,” he said. “You have a couple of parents whose kid volunteered to fight in a distant land, who they hadn’t seen in five years and weren’t sure if they would ever see again.”



He added: “I write too many letters to folks who unfortunately don’t see their children again after fighting a war.”



It is the second time this week that Obama has been pressed on the Bergdahl affair during his European tour. The controversy is dominating the political agenda in Washington, fuelled by Republican strategists seeking to pummel Obama five months out from crucial midterm elections.



Interviews with angry members of Bergdahl's platoon – the source of much of the criticism of the soldier's alleged disloyalty – have on at least one occasion been arranged by a public relations firm with strong links to the Republican party.



Congressional critics are also complaining the administration bypassed a statutory obligation to consult with Congress at least a month before the release of Guantánamo prisoners.



The US president maintained that legislators had been given advance notice that an exchange was a possibility and said it was impractical, and potentially dangerous for Bergdahl, to effectively make the prisoner swap public before it occurred.



“We had discussed with Congress the possibility that something like this might occur,” he said. “Because of the nature of the folks that we were dealing with and the fragile nature of these negotiations, we felt it was important to go ahead and do what we did.”



On Thursday, the Associated Press, citing "three congressional officials," reported that the administration has told senators it didn't talk to Congress about the deal because the Taliban had threatened to kill Bergdahl if news of the talks leaked before the swap was made.

Marie Harf, the State Department's deputy spokesperson, declined to say whether the Obama administration received a specific threat from the Taliban that it would kill Bergdahl if the deal was made public. But she added that once the agreement to pursue the swap was finalised, US officials did have new concerns about Bergdahl's safety.

"Someone guarding him who possibly wouldn't agree [with the exchange deal] could take harmful action against him," she said.

Bergdahl remains in a military hospital in Germany, where he is recovering from his ordeal and being debriefed by the US army.

“He remains in stable condition. His health continues to improve daily. He is conversing with medical staff and becoming more engaged in his treatment plan. He is resting better,” Pentagon spokesman Colonel Steve Warren said in a statement released Thursday.

In a sign of how the political mood surrounding Bergdahl’s has shifted, a welcome home party in his hometown of Hailey, Idaho, where locals were ecstatic at the news of his release at the weekend, has been cancelled.