Graham: Snowden has 'gotten some people killed probably'

Earlier Thursday, Russian authorities announced Snowden would be granted temporary asylum for the next year, allowing him to leave the Moscow airport where he's been holed up for more than a month. 

The White House said they were "extremely disappointed" with the Kremlin, with press secretary Jay Carney indicating that President Obama could pull out of a scheduled bilateral summit in Moscow next month.

Pressed by Blitzer if there was evidence that Snowden had directly put American lives at risk, Graham said "a ton" exists, but that he could not share it publicly.

"I think people have been compromised in terms of how they represent our country; the way they operate overseas has been compromised," Graham said. "Yes, I'm very worried about sources and methods of the intelligence community being compromised.  I'm very worried about the diminished ability of this program to detect terrorist attacks before they come to our shores."

Lawmakers on both sides of the aisle have denounced Russia's decision to grant Snowden temporary asylum.

“Russia has stabbed us in the back, and each day that Mr. Snowden is allowed to roam free is another twist of the knife," Sen. Charles Schumer (D-N.Y.) said. "Others who have practiced civil disobedience in the past have stood up and faced the charges because they strongly believed in what they were doing. Mr. Snowden is a coward who has chosen to run."