"We have filed documents to extend his stay on the territory of Russia," attorney Anatoly Kucherena told the Russian news agency Interfax Wednesday.
The U.S. Justice Department has filed espionage charges against Snowden, 31, accusing him of leaking classified information. Felony charges were filed after he revealed a massive cache of information showing U.S. government surveillance of private citizens' e-mails, texts and telephone calls as it sought information on suspected terrorists.
He said he released the information to dramatize what he considered government violations of U.S. law. His disclosures damaged relations between the United States and several of its allies; U.S.-Russian relations were also stressed after Snowden was permitted to reside in Russia.
Snowden has said, in interviews, he would enjoy living elsewhere, and even return to the United States if he was assured a fair trial, but since no repatriation has been arranged, continuation of his Russian residency is likely his best opportunity. His current visa expires July 31.