Edward Snowden, the former National Security Agency contractor wanted by the United States for revealing highly classified surveillance programs, flew to Russia on Sunday and planned to head to Ecuador to seek asylum, the South American country's foreign minister and the anti-secrecy group WikiLeaks said.

Foreign Minister Ricardo Patino said his government has received a request for asylum from Snowden. WikiLeaks, which is giving Snowden legal assistance, said his asylum request would be formally processed once he arrived in Ecuador, the same country that has already been sheltering the anti-secrecy group's founder Julian Assange in its London embassy.

Snowden arrived in Moscow on an Aeroflot flight shortly after 5 p.m. local time Sunday after being allowed to leave Hong Kong, where he had been in hiding for several weeks after he revealed information on the highly classified spy programs.

Snowden was spending the night in Moscow's Sheremetyevo Airport and was booked on an Aeroflot flight to Cuba on Monday, the Russian news agencies ITAR-Tass and Interfax reported, citing unnamed airline officials. Aeroflot has no direct flights from Moscow to Quito, Ecuador; travelers would have to make connections in Paris, Rome or Washington, which could be problematic for Snowden.

Kristinn Hrafnsson, the WikiLeaks spokesman, told Britain's Sky News that Snowden would be meeting with diplomats from Ecuador in Moscow. WikiLeaks said he was being escorted by diplomats and legal advisers from the group.

The car of Ecuador's ambassador to Russia was parked outside the airport in the evening.

Assange, who has spent a year inside the Ecuadorean Embassy in London to avoid extradition to Sweden to face questioning about sex crime allegations, told the Sydney Morning Herald that WikiLeaks is in a position to help because it has expertise in international asylum and extradition law.

A U.S. official in Washington said Snowden's passport was annulled before he left Hong Kong, which could complicate but not thwart his travel plans. The U.S. official, who spoke on condition of anonymity for lack of authorization to discuss the matter, said that if a senior official in a country or airline ordered it, a country could overlook the withdrawn passport.

While Patino did not say if the asylum request would be accepted, Ecuador's President Rafael Correa has shown repeated willingness to irk the U.S. government and he has emerged as one of the leaders of Latin America's leftist bloc, along with Fidel and Raul Castro of Cuba and Venezuela's late President Hugo Chavez.

Both the United States and Britain protested his decision to grant asylum to Assange.

Critics have suggested that asylum for Assange might be aimed partly at blunting international criticism of Correa's own tough stance on critics and new restrictions imposed on the news media.

The White House said President Barack Obama has been briefed on Sunday's developments by his national security advisers.

Snowden's departure came a day after the United States made a formal request for his extradition and gave a pointed warning to Hong Kong against delaying the process of returning him to face trial in America.

The Department of Justice said only that it would "continue to discuss this matter with Hong Kong and pursue relevant law enforcement cooperation with other countries where Mr. Snowden may be attempting to travel."

The Hong Kong government said in a statement that Snowden left "on his own accord for a third country through a lawful and normal channel."

It acknowledged the U.S. extradition request, but said U.S. documentation did not "fully comply with the legal requirements under Hong Kong law." It said additional information was requested from Washington, but since the Hong Kong government "has yet to have sufficient information to process the request for provisional warrant of arrest, there is no legal basis to restrict Mr. Snowden from leaving Hong Kong."

The statement said Hong Kong had informed the U.S. of Snowden's departure. It added that it wanted more information about alleged hacking of computer systems in Hong Kong by U.S. government agencies which Snowden had revealed.

Hong Kong's decision to let Snowden go on a technicality appears to be a pragmatic move aimed at avoiding a drawn out extradition battle. The action swiftly eliminates a geopolitical headache that could have left Hong Kong facing pressure from both Washington and Beijing.

Russia has no interest in detaining Snowden

Russian officials have given no indication that they have any interest in detaining Snowden or any grounds to do so. Foreign Minister Sergey Lavrov has said that Russia would be willing to consider granting asylum if Snowden were to make such a request.

Russia and the United States have no extradition treaty that would oblige Russia to hand over a U.S. citizen at Washington's request.

The Cuban government had no comment on Snowden's movements or reports he might use Havana as a transit point.

Snowden's departure came as the South China Morning Post released new allegations from the former NSA contractor that U.S. hacking targets in China included the nation's cellphone companies and two universities hosting extensive Internet traffic hubs.

He told the newspaper that "the NSA does all kinds of things like hack Chinese cellphone companies to steal all of your SMS data." It added that Snowden said he had documents to support the hacking allegations, but the report did not identify the documents. It said he spoke to the newspaper in a June 12 interview.

'Gravely concerned' about cyberattacks

With a population of more than 1.3 billion, China has massive cellphone companies. China Mobile is the world's largest mobile network carrier with 735 million subscribers, followed by China Unicom with 258 million users and China Telecom with 172 million users.

Snowden said Tsinghua University in Beijing and Chinese University in Hong Kong, home of some of the country's major Internet traffic hubs, were targets of extensive hacking by U.S. spies this year. He said the NSA was focusing on so-called "network backbones" in China, through which enormous amounts of Internet data passes.

The Chinese Foreign Ministry said it was aware of the reports of Snowden's departure from Hong Kong to Moscow but did not know the specifics. It said the Chinese central government "always respects" Hong Kong's "handling of affairs in accordance with law." The Foreign Ministry also noted that it is "gravely concerned about the recently disclosed cyberattacks by relevant U.S. government agencies against China."

China's state-run media have used Snowden's allegations to poke back at Washington after the U.S. had spent the past several months pressuring China on its international spying operations.

A commentary published Sunday by the official Xinhua News Agency said Snowden's disclosures of U.S. spying activities in China have "put Washington in a really awkward situation."

"Washington should come clean about its record first. It owes ... an explanation to China and other countries it has allegedly spied on," it said. "It has to share with the world the range, extent and intent of its clandestine hacking programs."