US National Intelligence Head Says Snowden About to Reveal 'More Secrets'

"The assumption is that there are a lot more documents out there in escrow [to be revealed] at a time of his choosing," Clapper said Tuesday, speaking about Snowden's revelations, as quoted by The Washington Post. 

​The assessment of damage caused by Snowden's revelations has not been finished yet, however, its scale was quite significant, he added. 

​Snowden's revelations could cost him as much as 30 years in prison in the United States, where he is wanted on charges of espionage and theft of government property. Snowden had repeatedly stated that he would return to the United States if Washington guaranteed him a fair trial.