When it comes to getting soldiers back from war, Obama said, "We don't condition whether we make the effort to get them back."
He also said Bergdahl's health had been deteriorating and "We were deeply concerned about it.
"We saw an opportunity and we seized it. And I make no apologies for that," Obama said during a joint news conference with British Prime Minister David Cameron.
Bergdahl was released following a deal between the U.S. and the Taliban that was brokered by Qatar. Five Taliban detainees held in Guantanamo were released as part of the exchange. Republicans and Democrats have objected to the swap.
Obama said his administration had discussed the possibility of such an exchange with members of Congress in the past. But he did not notify lawmakers in advance that he planned to release Guantanamo detainees. He is required to provide such notice 30 days ahead of a release.
"Because of the nature of the folks that we were dealing with and the fragile nature of these negotiations, we felt it was important go ahead and do what we did," he said.
He also defended his announcement of the release, which he did Saturday at the White House with Bergdahl's parents at his side.
"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 whether they'd ever see again."
He said that as commander in chief of U.S. military forces, he has a responsibility for those soldiers.
"I make absolutely no apologies for making sure that we get back a young man to his parents and that the American people understand that this is somebody's child and that we don't condition whether we make the effort to get them back," he said.
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