The White House today said there was ample legal justification for former CIA contractor Edward Snowden to stand trial and asked Russia to return him to US.

Snowden, who has been stranded at the Moscow airport for three weeks now after his passport was withdrawn by the US, today applied for asylum in Russia. "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 Press Secretary Jay Carney told reporters.

"It should be clear, when we see the suppositions or discussions about the idea that Mr Snowden is somehow being persecuted, he is a United States citizen who has been charged with crimes, and under our system of law, he should be afforded every bit of due process here in the United States, and he should return here to face trial," he said.

Adding that this had been the US position in conversations with Russians on the issue, Carney added: "Our interest has always been in seeing him expelled from Russia and returned to the United State," Carney said.