(CNN) -- Obama administration officials showed a so-called "Proof of Life" video of Bowe Bergdahl at a classified Senate briefing on Wednesday, but the session failed to convince numerous skeptics that swapping Taliban terror detainees for the captured Army sergeant was the right thing to do.
"I remain as deeply skeptical about this as I did before this conversation that we just had with the administration. For two days now, we've asked questions, many of which have not yet been fully answered," Sen. Marco Rubio, a Republican of Florida, told CNN after the briefing.
Since announcing Bergdahl's release this past weekend, administration officials have said they fast-tracked the operation over concerns about his health and safety, which appeared to be in jeopardy.
A senior defense official said on Wednesday that recent intelligence, in addition to two proof-of-life videos released in recent months, underscored the concerns.
CNN has reported on the existence of the most recent video, believed to be recorded last December, which U.S. officials have said showed a marked deterioration in Bergdahl's condition.
Lawmakers emerging from the closed session had mixed reaction as to whether his health was evidence that he needed to be immediately freed.
Sen. Mark Kirk, an Illinois Republican, said Bergdahl "didn't look good. I understand the emotional power the video had on the President."
President Barack Obama has defended his decision to get Bergdahl back now, saying he was not going to leave him behind with the United States in the final stage of its Afghanistan operation.
Bergdahl was the only remaining U.S. military captive from the conflicts in Iraq and Afghanistan.
The video was short, and Bergdahl spoke English, said Kirk. He spoke softly and slowly, almost slurring. There were references to the recent death of Nelson Mandela in the video.
Kirk said there was no new information from the officials who briefed the senators on what Bergdahl's ailments were.
"His condition in the video made it clear he was not in good condition and this was a proof of life video we insisted on before negotiations commenced. Once having seen it, as we saw it, I'm sure there was great concern about his condition," Democrat Richard Durbin of Illinois said.
Democratic Sen. Joe Manchin of West Virginia, like several other senators, was skeptical the video provided enough evidence to warrant the extraordinary prisoner swap that some lawmakers called too open ended and could possibly have repercussions for American security down the road.
"You could tell he had been drugged and he was in a different state," Manchin said.
Adding later: "That did not sell me at all. The proof of life was five months ago, December ... That was not the person who was released here. He was not in that dire situation when he was released."
Others noted that it took five months for the White House to cut a deal to free Bergdhal after seeing the video.
Complex negotiations were conducted through the government of Qatar, which accepted the transfer of the five Taliban prisoners who had been held for years at the U.S. detention facility at Guantanamo Bay, Cuba.
Several senators said the video should be made public. It's not clear if that will happen.
The administration officials told the senators that none of the detainees in question were involved in attacks against the United States.
"I'm a little bit more reassured" of the President's decision, Kirk said, adding, however, that the administration could not guarantee that the former detainees wouldn't return to the battlefield.
Republicans and Democrats raised serious concerns more than two years ago with the administration about the possibility of such a swap but said promised consultation never materialized.
In all discussions and the private communications about such a step, there were exchanges about possible conditions placed on the detainees -- including renouncing al Qaeda and violence in the region. But those terms were not included in the final deal.
CNN's Dana Davidsen contributed to this report.