HONG KONG -- The State Department has asked Hong Kong to extradite Edward J. Snowden to face espionage and theft charges in the United States, officials confirmed on Saturday, setting off what is likely to be a tangled and protracted fight over his fate.
Tom Donilon, President Obama's national security adviser, told CBS Radio News that the request makes "a good case" under the extradition treaty between the United States and Hong Kong for the return of Mr. Snowden, the former National Security Agency contractor whose disclosures about American surveillance programs have riveted the country. "Hong Kong has been a historically good partner of the United States in law enforcement matters, and we expect them to comply with the treaty in this case," Mr. Donilon said.
A public battle over the status of Mr. Snowden could prove uncomfortable for the Obama administration. His revelations have provoked new criticism of the N.S.A.'s eavesdropping and data collection, and a drawn-out legal struggle could put a harsh spotlight on the tension between President Obama's pledges of transparency and civil liberties and his administration's persistent secrecy and unprecedented leak prosecutions.
For the past week, Mr. Snowden, 30, appears to have been staying in an apartment in Hong Kong's Western District that is controlled by the Hong Kong government's security branch, according to a person who has followed the case and spoke on the condition of anonymity. Mr. Snowden appears to have been granted access to the apartment after seeking protection from the Hong Kong police against a possible rendition attempt by the United States, the person said.
Mr. Snowden left a hotel room in Hong Kong two weeks ago after revealing that he was the one who leaked highly classified documents to The Guardian and The Washington Post. Hong Kong police officials would not comment on Saturday about Mr. Snowden's whereabouts.
Stephen Vickers, who oversaw police criminal intelligence in Hong Kong before Britain returned the territory to China in 1997, said Saturday that the police should be able to detain him once Hong Kong government lawyers have determined the charges Mr. Snowden faces in the United States are also illegal offenses in Hong Kong.
"I have no doubt whenever the government decides to take action, they will pick him up fast," said Mr. Vickers, who now runs a risk consulting firm.
If and when the Hong Kong police detain him, Mr. Snowden can then appeal to a magistrate for his release. But he faces another complication: his 90-day tourist visa runs out in mid-August, giving the local authorities another reason to keep him in custody.
The more daunting challenge facing the United States is its expected request to have Mr. Snowden sent back to America to face criminal charges in the Eastern District of Virginia, where prosecutors have handled many major national security cases.
A senior Obama administration official suggested on Saturday that strong pressure was being applied privately on Hong Kong authorities to swiftly return Mr. Snowden. "If Hong Kong doesn't act soon, it will complicate our bilateral relations and raise questions about Hong Kong's commitment to the rule of law," the official said.
But the request faces both political and legal complications.
In recent weeks, Mr. Snowden's plight has been seized on by multiple groups: by Hong Kong's human rights movement, by pro-Beijing activists attracted to his defiance of the United States, and by those angered by Mr. Snowden's claims that Hong Kong was itself the target of aggressive American surveillance efforts. And with such a potent issue stirring passions here and abroad, lawyers are likely to swarm over the high-profile case. (Mr. Snowden's legal advisers have yet to come forward.)
Mr. Snowden and his lawyers could tie up any effort to have him sent back to the United States by asserting that "his offense is a political offense," said Regina Ip, a former Hong Kong secretary of security and a current legislator. She added that such an assertion would have "to go through various levels of our courts." The United States' surrender treaty with Hong Kong has an exception for political offenses.
Alternatively, Mr. Snowden could apply for asylum. Currently, asylum claims are facing lengthy delays of several years in Hong Kong, since they are handled by Hong Kong officials in cooperation with the office of the United Nations High Commissioner for Refugees. Nazneen Farooqi, a local protection officer with the United Nations refugee agency, suggested last week, without addressing Mr. Snowden's case directly, that his case would not be fast-tracked should he go this route, since, "We prioritize older cases." And people who make asylum applications can be held in detention for weeks, months or even longer.
Finally, China could also apply behind-the-scenes pressure to slow down or block the effort to have Mr. Snowden turned over. Hong Kong enjoys legal autonomy from mainland China, but the Chinese government can intervene in diplomatic and defense matters.
While Chinese officials have steered away from commenting on the specifics of Mr. Snowden's case, government and news outlets controlled by the Communist Party have been increasingly sympathetic to Mr. Snowden, with an opinion article in the state-run China Daily suggesting Thursday that "Snowden's crime, if any, pales in comparison with the actions of the U.S. officials who authorized and operated the cyberespionage program."
Overwhelming majorities in both parties in Congress appear to support the prosecution of Mr. Snowden. But his revelations have already produced some uncomfortable moments for the administration: a Republican congressman who helped write the Patriot Act, Representative Jim Sensenbrenner of Wisconsin, declared one leaked N.S.A. program "un-American," and the director of national intelligence, James R. Clapper Jr., was forced to admit that his previous statement to Congress that the agency did not collect records on millions of Americans was untrue.
Mr. Snowden is the seventh person to be accused by the Obama administration of violating the Espionage Act of 1917 by leaking secrets to the news media, compared with three such cases under all previous presidents. And unlike others accused of leaking, Mr. Snowden went public with his own explanation of his actions before he was charged, giving a series of interviews to The Guardian and portraying the leaks as an act of conscience intended to give Americans a chance to decide the appropriate limits of spying. He has drawn support from a wide swath of the political left and the libertarian right in the United States.
Even if he is silenced by the Hong Kong authorities during a removal battle, his supporters will echo and amplify his claim to have acted in the interest of democracy. Mr. Obama, who said after the leaks surfaced that he welcomed a debate over surveillance programs, will preside symbolically over the pursuit and punishment of the man who started the debate.
"For better or worse, it's the president's prerogative to decide what's classified and what's not," said Stephen Vladeck, a law professor at American University. "But it's reasonable to think that the administration deserves some blame for leaving it to people like Snowden to start a public debate on these issues."
Gerry Mullany reported from Hong Kong, and Scott Shane from Baltimore. Sarah Lyall contributed reporting from London.
This article originally appeared in The New York Times.