While discussing the contentious confirmation hearings for defense secretary nominee Chuck Hagel, things got a bit heated on Sunday's "Meet The Press" when Sen. John McCain referred to the lack of information from the White House surrounding the Sept. 11, 2012 attacks in Benghazi as a "massive cover-up."

"There are so many answers we don't know," McCain told host David Gregory. "We've had two movies about getting bin Laden and we don't even know who the people were who were evacuated from the consulate the day after the [Benghazi] attack. So there are many, many questions. So we've had a massive cover-up on the part of the administration."

Gregory then pressed McCain on what the Arizona senator meant by "a massive cover-up."

"I'm asking you, do you care whether four Americans died?" McCain said. "And shouldn't people be held accountable for the fact that four Americans died?"

"Well, what you said was the cover-up--a cover-up of what?" Gregory asked.

"Of the information concerning the deaths of four brave Americans," McCain replied. "The information has not been forthcoming. You obviously believe that it has. I know that it hasn't. And I'll be glad to send you a list of the questions that have not been answered, including 'What did the president do and who did he talk to the night of the attack on Benghazi?'"

McCain continued: "Why did the president for two weeks, for two weeks during the heat of the campaign continue to say he didn't know whether it was a terrorist attack or not? Is it because it interfered with the line 'Al Qaeda has [been] decimated'? And 'everything's fine in that in that part of the world'? Maybe. We don't know. But we need the answers. Then we'll reach conclusions. But we have not received the answers. And that's a fact."

Earlier, the former Republican presidential nominee said he expects Hagel to be confirmed as defense secretary even though he doesn't plan to vote for him.

"I don't believe he is qualified," McCain said. "But I don't believe that we should hold up his nomination any further."