U.S. defense contractor Edward Snowden discusses his motivation behind the NSA leak and why he is revealing himself as the whistleblower behind the major story. (Nicki Demarco/Courtesy of Laura Poitras and Glenn Greenwald)

Edward Snowden, the former government contractor who leaked top-secret documents about U.S. surveillance programs, fled Hong Kong for Moscow on Sunday with the assistance of the anti-secrecy organization WikiLeaks and asked the government of Ecuador to grant him asylum.

Snowden’s ultimate destination was uncertain, but Ricardo Patiño, Ecuador’s foreign minister, tweeted Sunday afternoon that his government had received a request for asylum from Snowden. WikiLeaks released a statement saying Snowden was “bound for the Republic of Ecuador via a safe route for the purposes of asylum.”

According to the Associated Press, Snowden is set to leave Moscow for Havana Monday on an Aeroflot flight that leaves at 2:05 p.m. (6:05 a.m. EDT).

Despite U.S. officials’ insistence that Snowden’s passport was revoked Saturday, the Hong Kong government said Sunday that he left “on his own accord for a third country.”

Aeroflot told the Associated Press that Snowden registered for the flight on Sunday using his U.S. passport.

Ecuadoran diplomats were at Sheremetyevo International Airport, where Snowden landed aboard an Aeroflot flight about 5:05 p.m. (9:05 a.m. EDT). It was not clear whether they were meeting with Snowden or with others who accompanied him. Snowden did not have a Russian visa, according to several sources, so he was confined to a transit area within the airport.

WikiLeaks, which has published hundreds of thousands of classified documents over the past several years, said it is aiding Snowden in his bid to avoid a return to the United States. Snowden, 30, had fled to Hong Kong, where he revealed two weeks ago that he was the source of leaked National Security Agency documents. Federal prosecutors in Virginia filed espionage charges against him June 14 and had asked Hong Kong to detain him.

“The U.S. is disappointed and disagrees with the determination by Hong Kong authorities not to honor the U.S. request for the arrest of the fugitive, Edward J. Snowden,” a Justice Department spokesman said Sunday. The spokesman, who declined to be identified, added that authorities in the United States and Hong Kong had “been in continual contact” since June 10, when the Justice Department learned that Snowden was in the Chinese territory.

WikiLeaks said Snowden was accompanied on his flight to Moscow by Sarah Harrison, who the organization said is a British citizen, journalist and researcher working with the WikiLeaks legal defense team.

Kristinn Hrafnsson, an Icelandic investigative journalist and spokesman for WikiLeaks, said in a phone interview that Snowden would overnight in Moscow, which he described as “not a final destination.” He declined to say when Snowden would be departing or where his final stop would be.

Hrafnsson said he established contact with Snowden last week while the American was in Hong Kong. Arrangements were made for Harrison to meet Snowden in Hong Kong and accompany him out. Harrison was still with Snowden in Moscow, Hrafnsson said.

“The WikiLeaks legal team and I are interested in preserving Mr. Snowden’s rights and protecting him as a person,” said Baltasar Garzón, legal director of WikiLeaks and attorney for Julian Assange, the group’s founder, who has spent the past year holed up in the Ecuadoran Embassy in London. “What is being done to Mr. Snowden and to Mr. Julian Assange — for making or facilitating disclosures in the public interest — is an assault against the people.”

The flight of Edward Snowden

U.S. officials, who spoke on the condition of anonymity because of ongoing diplomacy regarding Snowden, said his passport had been revoked before he left Hong Kong.

The State Department said privacy laws prevented it from commenting on Snowden’s passport.

“As is routine and consistent with U.S. regulations, persons with felony arrest warrants are subject to having their passport revoked,” said State Department spokeswoman Jen Psaki. “. . . Persons wanted on felony charges, such as Mr. Snowden, should not be allowed to proceed in any further international travel, other than is necessary to return him to the United States.”

But the Interfax news agency, quoting a Russian law enforcement source, said Snowden could continue on his journey from Moscow without a U.S. passport if the country where he was seeking asylum provided him with travel documents. Those documents could include affirmation of refugee status, Interfax reported, or even a passport from the destination country.

In a statement Sunday night, NSC spokeswoman Caitlin Hayden said: “We are disappointed by the decision of the authorities in Hong Kong to permit Mr. Snowden to flee despite the legally valid U.S. request to arrest him for purposes of his extradition under the U.S.-Hong Kong Surrender Agreement. We have registered our strong objections to the authorities in Hong Kong as well as to the Chinese government through diplomatic channels and noted that such behavior is detrimental to U.S.-Hong Kong and U.S.-China bilateral relations.”

Given Russia’s recent intense cooperation with the United States after the Boston Marathon bombing and the nation’s history of working with Russia on law enforcement matters, she added, “We expect the Russian Government to look at all options available to expel Mr. Snowden back to the U.S. to face justice for the crimes with which he is charged.”

Russia’s role under fire

The apparent cooperation of the Russian government in Snowden’s attempt to avoid extradition to the United States outraged some members of Congress.

“What’s infuriating here is [President Vladimir] Putin of Russia aiding and abetting Snowden’s escape,” Sen. Charles E. Schumer (D-N.Y.) said on CNN’s “State of the Union.”

“The bottom line is very simple,” Schumer said. “Allies are supposed to treat each other in decent ways, and Putin always seems almost eager to put a finger in the eye of the United States, whether it is Syria, Iran and now, of course, with Snowden. That’s not how allies should treat one another, and I think it will have serious consequences for the United States-Russia relationship.”

Rep. Ileana Ros-Lehtinen (R-Fla.) agreed that Sunday’s events call “into question what kind of relationship we ever have had with China and Russia. We pretend that everything is hunky-dory when it is not. It isn’t with China. It isn’t with Russia. It certainly isn’t with Cuba, with Venezuela nor with Ecuador.”

She added: “These are countries that violate press freedoms every day. And yet [Snowden]’s seeking political asylum in those very countries where . . . if he were to pull a Snowden in these countries, they’d jail him immediately.”

Hong Kong’s government said that the U.S. request for a warrant for Snowden’s arrest “did not fully comply with the legal requirements under Hong Kong law” and that it had asked for “additional information.”

“As the HKSAR 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.

A senior Justice Department official disputed that claim. “The request met the requirements of the agreement,” said the official, who spoke on the condition of anonymity. “They came back to us late Friday with additional questions, and we were in the process of responding. Obviously, this raises concerns for us, and we will continue to discuss this with the authorities there.”

The United States had asked Hong Kong to issue a provisional arrest warrant and filed charges against Snowden, including theft, “unauthorized communication of national defense information” and “willful communication of classified communications intelligence information to an unauthorized person.”

If Snowden is relocating to Ecuador, he will have limited travel options. There are no direct flights from Moscow to Quito, and many would-be layover destinations would probably heed Washington’s request to detain him. One likely exception would be Havana. There are direct flights from Moscow to Havana five days a week, including Mondays, and a direct flight from Havana to Quito on Fridays.

Patiño, the Ecuadoran foreign minister, recently said Quito would be willing to consider an asylum claim by Snowden. Speaking at a news conference in London after visiting Assange last Monday, Patiño suggested that his nation would approve such a request.

On Monday, Patiño was in Vietnam and said that the nation is “in touch with the highest authorities of Russia” about an asylum claim from Snowden, according to the Associated Press. He said that the request “has to do with freedom of expression and with the security of citizens around the world,” and that Ecuador will not make its decision based on its relationship with the United States.

“There are some governments that act more upon their own interests, but we do not,” Patiño said, according to the Associated Press. “We act upon our principles.”

He added, “We take care of the human rights of the people.”

Assange has been unable to leave the Ecuadoran Embassy because Britain has refused to provide him safe passage while he is sought by Sweden for questioning about sexual-assault allegations.

U.S. relations with Ecuador

Ecuadoran President Rafael Correa has emerged as one of the most vehement critics of U.S. policy in the Western Hemisphere. In 2011, his administration expelled the American ambassador in Quito to protest a cable released by WikiLeaks that alleged the Ecuadoran police force was rife with corruption.

The extradition treaty between the United States and Ecuador, signed in 1872, states that offenses of “a political character” do not warrant extradition — much like the United States’ agreement with Hong Kong.

It’s unclear whether the Chinese leadership in Beijing had any role in Hong Kong’s decision to let Snowden leave. Hong Kong is a semiautonomous region that prides itself on its independent legal system, but the government ultimately answers to the mainland, whose influence can be difficult to discern. Residents in Hong Kong are deeply resistant to any overt sign of interference from the Communist Party.

The Ministry of Foreign Affairs in Beijing said in a statement Sunday that it had seen the reports of Snowden’s departure and would continue to pay attention to developments but did not have “specific details.” The government added that it was “deeply concerned” about reports of U.S. government cyberattacks on China, saying they “proved that China is a victim of cyberattacks.”

Faiola reported from London and Yang reported from Hong Kong. Ernesto Londoño in Kabul, Sari Horwitz, Juan Forero in Bogota, Colombia, Lenny Bernstein and David Nakamura in Washington, and Liu Liu in Beijing contributed to this report.