Former US spy agency contractor Edward Snowden, who is wanted in the US on espionage charges, has requested temporary asylum in Russia, officials have said.

Russian officials and lawyer Anatoly Kucherena confirmed on Tuesday that Snowden had filed an application for temporary asylum, although he has said he wants eventually to travel to Latin America.

The US appealed once again to Moscow on Tuesday to expel Snowden. "Our position on this remains what it was and is quite clear, which is that we believe there is ample legal justification for the return of Mr Snowden to the United States, where he has been charged with serious felonies," White House spokesman Jay Carney said.

Snowden, who revealed details of the US government surveillance programmes, has been stranded at a Moscow airport since June 23.

Al Jazeera's Yulia Shcherbina, reporting from Moscow, said that a federal migration service officer was invited to Moscow's Sheremetyevo International Airport because the fugitive whistleblower could not leave the transit zone.

"He has written the request and submitted it," Shcherbina said.

Vladimir Putin, Russia's president, characterised Snowden earlier as an unwelcome present from the US.

When asked what will happen to Snowden, Putin said: ""How should I know? It's his life and his fate."

Putin said that the US had blocked all travel options for Snowden, who had planned only a transit stop in Moscow.

"We weren't his final destination," said Putin, who made the comments while speaking to students on a Russian island in the Gulf of Finland.

"He was flying to other states. As soon as there's the chance to move somewhere he will certainly do this."

Asylum question

Snowden was checked in for a flight from Moscow to Havana, Cuba on June 24 but never boarded the plane. His passport has been revoked by Washington, Snowden has been stranded in the airport's transit zone for the past three weeks.

On Friday he said at the airport that he was seeking temporary asylum in Russia before he could safely travel to Latin America. The status of that application is unclear.

The Russian president conspicuously refrained from indicating if or when he might grant asylum to Snowden. Putin said earlier this month that Snowden could claim asylum in Russia only if he stopped his leaks. Venezuela, Bolivia and Nicaragua have offered him asylum.

Washington has reacted sharply to the possibility that Moscow might offer Snowden a safe haven and accused it of providing him a propaganda platform.

Putin,who is set to host the US President, Barack Obama, for a bilateral summit in Moscow followed by the G20 summit in Saint Petersburg in early September, reiterated Russia's refusal to damage ties with Washington for Snowden's sake.