Edward Snowden, the fugitive former contractor who leaked classified National Security Agency documents, "was a thief" who had possible Russian assistance and has "incredibly harmed" the U.S. military, the House Intelligence Committee chairman said.

"This was a thief, who we believe had some help, who stole information, the vast majority had nothing to do with privacy," Rep. Mike Rogers, a Michigan Republican, said on the NBC News program "Meet the Press" broadcast Sunday.

"Our army, navy, air force, marines have been incredibly harmed by the data that he has taken with him and we believe now is in the hands of nation states."