Moscow, July 13, 2013 - Russia on Saturday faced stark warnings from the United States against granting asylum to fugitive US leaker Edward Snowden after he broke three weeks of silence to tell activists he wanted sanctuary in the country.

Snowden on Friday dramatically summoned activists to the transit zone of Moscow's Sheremetyevo airport where he has been marooned without a valid passport for the last three weeks after arriving on a flight from Hong Kong.

The United States wants the former National Security Agency (NSA) contractor extradited back home to face justice over his leaking of sensational details about US surveillance activities, a demand Moscow has so far rejected.

In an indication that already tense US-Russia ties could strain further over the affair, the White House warned Russia not to grant Snowden a “propaganda platform” as top allies of President Vladimir Putin argued he should be given sanctuary.

Snowden, 30, making his first publicised appearance since arriving in Moscow, told the activists he wanted to claim asylum in Russia until he could safely travel to win permanent sanctuary in Latin America.

“I ask for your assistance in requesting guarantees of safe passage... in securing my travel to Latin America, as well as requesting asylum in Russia until such time as... my legal travel is permitted,” Snowden said.

He said that the asylum request was being made Friday evening.

The head of Russia's Federal Migration Service (FMS) Konstantin Romodanovsky said early Saturday that Moscow had yet to receive the application which, if it arrived, would be examined “according to normal legal procedures”.

Prominent Russian lawyer Anatoly Kucherena, who attended the meeting and promised to help Snowden, told Russian television that the asylum request procedure could take up to three weeks. But hinting that Snowden's new application may be viewed positively, the speaker of Russia's lower house of parliament Sergei Naryshkin and the upper house speaker Valentina Matviyenko both swiftly said his request should be accepted.

Naryshkin, a powerful ally of Putin who used to head the Kremlin administration, said that Snowden was a “defender of human rights” who risked facing the death penalty if he was sent back to the United States.

'He is not a phantom'

The almost surreal meeting saw the group of less than a dozen activists arrive at the airport to be surrounded by a huge crowd of journalists. They were then ushered away by an airport official clutching a sign labelled “G9” to a secure area to meet the hitherto invisible fugitive.

Those invited, who received a personal email from Snowden sent Thursday evening, included representatives of Amnesty International and Human Rights Watch as well as prominent Moscow lawyers.

“He is not a phantom, he is a live human being,” commented Russian lawyer Genri Reznik after meeting Snowden, who had not been sighted once until now since arriving at the airport.

Russian state television late Friday broadcast footage shot from a mobile phone of the meeting, which showed Snowden reading out a statement while flanked by a staffer from the WikiLeaks anti-secrecy website, Sarah Harrison, and a woman interpreter.

He appeared well and spoke confidently.

“We walked in and there he was: Mr Snowden waiting for us,” said Tanya Lokshina, senior researcher at HRW in Moscow in a blog on the group's website.

“The first thing I thought was how young he looks - like a school kid.”Curiously, Snowden had last week withdrawn a request for asylum in Russia after Putin insisted he could stay only if he stopped releasing information that harmed the United States.

At the meeting with activists, Snowden vowed he did not want to harm the United States but it was not clear whether this meant he was prepared to stop leaking in order to stay in Russia.

Although several leftist Latin American states have indicated a readiness to host him, Snowden said at the meeting that Western governments would prevent him from travelling there.

The United States has already rebuked China for allowing Snowden to leave for Russia from Hong Kong and Moscow would risk incurring the wrath of Washington should it dare offer him asylum. US-Russia ties are already strained over human rights and the conflict in Syria.

“We would urge the Russian government to afford human rights organisations the ability to do their work in Russia throughout Russia, not just at the Moscow transit lounge,” White House spokesman Jay Carney said.

US President Barack Obama spoke to Putin by telephone Friday on issues including the Snowden affair, the Kremlin and White House both said, but no further details were forthcoming.