The former U.S. intelligence contractor who disclosed that the National Security Agency spied on citizens says there is a "zero percent chance" Russia or China has classified NSA documents.
In a New York Times interview published Thursday, Edward Snowden said he gave all such documents in his possession to journalists in Hong Kong.
Snowden said taking the files with him when he fled to Moscow would not have served the public interest.
The former contractor also says he was highly familiar with Chinese cyber-counterintelligence and that the NSA knows he protected the classified information from China's spies.
Snowden revealed earlier this year that the NSA collected records of communications by U.S. citizens.
Snowden said he decided to speak out after discovering an internal NSA report, on wiretapping by the Bush administration, without court orders. Snowden said the program skirted the existing surveillance laws.
He told the Times that if the highest officials in government can break the law without punishment, then "secret powers become tremendously dangerous."
Snowden fled to Hong Kong and then to Moscow after disclosing the NSA spy program. Russian President Vladimir Putin granted him a year's asylum, angering the United States which wants to put him on trial.
The NSA has not commented on Snowden's remarks to The New York Times, but has defended its surveillance program, saying it helped foil several major terrorist plots.