NSA chief James Clapper says Snowden leaks caused 'profound damage' to US security

Director of the US National Intelligence, James Clapper, has reportedly said that the revelations made by whistleblower Edward Snowden have caused 'profound damage' and called for the return of 'stolen' documents.

Clapper said that Snowden's revelations led to a loss of critical foreign intelligence collection sources, including those shared with the US by valued partners.

According to the BBC, the NSA chief said that Snowden's leaks had gone way beyond his professed concerns about domestic spying and if his 'mission' has been accomplished, then he and his accomplices should facilitate the return of the remaining documents, which have not been exposed yet.

The 30-year-old, charged with espionage by the US, revealed classified data about the alleged mass surveillance programmes carried out by the US and the UK on innocent citizens and global leaders as part of counter-terrorism project.

However, the scale of the indiscriminate snooping led to fury amongst citizens and upset US' ties with its allies.

Meanwhile, Snowden has claimed that he no longer possessed copies of the classified documents, which he handed over to the news organizations before fleeing the US and seeking temporary refuge in Russia.