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.
Hong Kong, a former British colony, has a high degree of autonomy and is granted rights and freedoms not seen on mainland China, but under the city's mini constitution Beijing is allowed to intervene in matters involving defense and diplomatic affairs. Hong Kong has an extradition treaty with the U.S., but the document has some exceptions, including for crimes deemed political.
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 latest travels 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.
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."