MOSCOW - The United States does not ask Russia to extradite Edward Snowden but just wants him returned, US ambassador to Russia Michael McFaul said Thursday.

"The US doesn't ask to 'extradite' but simply to return Mr. Snowden," he wrote in his Twitter account.

The diplomat pointed out that his country sent back to Russia many people wanted by Russian authorities despite the fact that there is no re-admission agreement between the two countries.

The White House said Wednesday that the United States was seeking an explanation from the Russian authorities on the status of Snowden, who has stayed in the transit zone of Sheremetyevo airport in Moscow for a month.

White House press secretary Jay Carney repeated Washington's position that there is "ample precedent and legal justification" for Moscow to hand over Snowden to face charges in the United States for "unauthorized leaking of highly classified information."

On the same day, speculation that Snowden had been granted approval to leave the airport was quashed by his lawyer, Anatoly Kucherena.

Snowden is still waiting on his temporary asylum request in Russia, Kucherena told reporters after meeting Snowden in Terminal E of the airport.

According to Kucherena, the Federal Migration Service (FMS) had not yet granted the necessary certificate.

If the service rejected the application, Snowden could appeal, the lawyer added.

Eugeny Varshavsky, a former head of the FMS' Department for Legal Support, told Xinhua that the delay of the certificate did not necessarily mean that his application had been rejected.

As it is a high-profile case, the FMS needs to receive orders from upper authorities, Varshavsky said.

"If the political will is manifested clearly, the FMS will make a swift decision," he added.

Kucherena said his next meeting with Snowden would depend on "when he asks me to come."

He has given Snowden some clothes and several books for him to learn Russian. The lawyer said Snowden plans to find a job in Moscow if asylum is granted.