Former National Security Agency contractor Edward Snowden has formally asked Russia to extend his asylum, which expires on July 31.

The American whistleblower faces charges in the United States for leaking details of mass government surveillance.

He arrived in Moscow on June 24 last year after a flight from Hong Kong, and was stranded in the airport for weeks with a voided passport before being granted asylum.

Snowden’s revelations last year angered some of the US’s European allies whose high-ranking officials had been targeted by the spy agency.

RT quoted Snowden lawyer, Anatoly Kucherena, as saying that Snowden had requested another year of asylum. “We have submitted documents to prolong his stay in Russia,” Kucherena said Wednesday.

Moscow’s decision to give asylum to the whistleblower was strongly criticized by Washington. The US has been seeking Snowden’s extradition to face espionage charges.

Snowden has recently increased his media visibility in Russia by giving several interviews, in which he has conceded that he would like to go home.

His decision to extend his asylum came as prosecutors in Germany searched the home of a US defense ministry employee suspected of spying - the second such case in a week.

Washington has not denied allegations that the intelligence agency employee arrested earlier this month was passing secret documents to the NSA.

The relations between the US and Germany were strained last year after Snowden’s documents revealed that the NSA had been monitoring German Chancellor Angela Merkel's cellphone calls.

ARA/ARA

Putin told him not to publish any more documents that would cause the USA trouble.