They reportedly showed the lawmakers a "proof of life" video and said the Taliban had threatened to kill Bergdahl if the deal wasn't finalized.
"In fact, the briefing is still going on, but I don't see how anybody can walk out of there with any kind of comfortable feeling that the administration from a notification standpoint -- and I emphasize that -- did what they should have done or what they had the opportunity to do," he said. "I mean, it was like they didn't trust [Sen. Dianne Feinstein (D-Calif.)] and me. And, yet, the two of us knew about the bin Laden event for -- leading up to the takedown of bin Laden -- for months and months and months. And it's just very puzzling as to why they didn't notify anybody in Congress as to what was going on."
Sen. John McCain, R-Ariz., attended the briefing, but left after his one question received an answer he deemed unsatisfactory. McCain, a former Vietnam prisoner of war, has been an outspoken opponent of how the Bergdahl deal was handled.
"I learned nothing," McCain told reporters after he left the briefing.
Sen. Rand Paul, R-Ky., who has been highly critical of the White House's approach to the situation, did not attend the briefing at all.
Notable deaths of 2014 [PHOTOS]