The risks to Sgt. Bowe Bergdahl were growing as officials negotiated his release from Taliban captivity, Defense Secretary Chuck Hagel told Congress on Wednesday in a public defense of the Obama administration's controversial prisoner swap.

Testifying before the House Armed Services Committee, Hagel faced tough questioning from lawmakers, including U.S. Rep. John Kline, who remain skeptical of the prisoner exchange.

"The United States did set a precedent, did break the policy of negotiating with terrorists," Kline told Hagel during the hearing.

The decision to trade five Taliban leaders for the release of Bergdahl, who was held for five years, has come under intense criticism on Capitol Hill. Lawmakers were not notified of the deal in advance.

"Who specifically selected the particular detainees that were transferred?" Kline asked Hagel.

"We've had some tortuous legal responses to questions we're trying to get at ... we're just trying to find out the basics," Kline later said.. "I hope you can see why there's a lot of confusion here."

Hagel described the negotiations for Bergdahl's release as "imperfect" and "imprecise."

"I know there are differences and I know there are questions and I get it," Hagel said in response to Kline's questioning. "But we did get him back."