WASHINGTON — Defense Secretary Chuck Hagel told Congress today that officials of Qatar negotiating the release of captured Army Sgt. Bowe Bergdahl told the U.S. that “time was not on our side” and a leak about the exchange would sabotage the deal.

Hagel testified at a House Armed Services Committee hearing that the decision to transfer five Guantanamo Bay, Cuba, detainees into Qatar’s hands in exchange for Bergdahl was a tough call for President Barack Obama. He called the five “enemy belligerents” who had not been implicated in any attacks against the U.S.

Hagel also said that Qatar has committed to adequate security measures that led him to decide the risks of the transfer were substantially mitigated.

Republicans and some Democrats have sharply criticized the Obama administration for not informing Congress in advance, with some accusing the president of breaking a law requiring 30-day notification of any Guantánamo prisoner release. Other questions center on whether Bergdahl deserted and whether the U.S. gave up too much for his freedom. Administration officials have told Congress that four of the five Taliban officials will likely rejoin the fight.

“This prisoner exchange was done legally,” Hagel told lawmakers.

Bergdahl, an Idaho native, had been held captive since 2009.

The Taliban officials had been at Guantánamo for more than a decade. Under the deal, they have to remain in Qatar for a year.