The classified documents that Snowden had downloaded from the U.S. National Security Agency were stored on smaller devices, such as hard drives and thumb drives, and they have not been turned over to the Russian or Chinese authorities, said Ray McGovern, a former Central Intelligence Agency analyst.

On Wednesday, Snowden held a six-hour meeting in Moscow with McGovern and three other former U.S. intelligence and law enforcement officials who have all become critics of government surveillance programs.