The U.S. failure to corral a national security fugitive has stirred up a diplomatic hornets’ nest that threatens to roil relations with China and Russia.

Edward Snowden, a former security contractor with access to classified information, landed in Moscow today after fleeing Hong Kong, which had rejected a U.S. warrant for his arrest. The anti-secrecy group WikiLeaks said on its website he is bound for Ecuador “via a safe route for the purposes of asylum, and is being escorted by diplomats and legal advisers from WikiLeaks.”

A U.S. official on Sunday said that Snowden’s passport had been annulled before he left Hong Kong for Russia. Snowden’s travel plans could be complicated – but not thwarted – by a lack of passport. The U.S. official said that if a senior official in a country or airline ordered it, a country could overlook the withdrawn passport.

The U.S. official would only discuss the passport on the condition of anonymity because the official was not authorized to discuss the matter.

In the U.S., lawmakers urged Russian President Vladimir Putin not to protect the fugitive, who has been charged with espionage.

Snowden’s departure from Hong Kong was “a very big surprise,” Senate Intelligence Committee Chairman Dianne Feinstein said today on “Face the Nation.”

“China clearly had a role in this, in my view,” said Feinstein, a California Democrat. “I don’t think this was just Hong Kong without Chinese acquiescence.”

New York Sen. Charles Schumer, the Senate’s third-ranked Democrat, called Hong Kong’s decision “very disappointing.”

“I have a feeling the hand of Beijing was involved here,” Schumer said in an interview on CNN’s “State of the Nation.”

Snowden is booked on a flight to the Venezuelan capital of Caracas through Moscow and Havana, according to an Aeroflot official who asked not to be identified because the information is confidential. Snowden requested political asylum in Ecuador, according to an earlier posting on Twitter by Ecuador’s foreign minister, Richard Patino Aroca.

The case threatens to strain already-weak U.S. ties with Russia, which has fought American extradition efforts in the past. Putin spokesman Dmitry Peskov, who has said that Russia might consider granting Snowden political asylum, said he had no information on his travel plans. The Russian Foreign Ministry’s press service, which said it was aware of reports that Snowden is transiting in Moscow, declined to comment further.

Schumer said if Putin knew and approved of Snowden’s trip to the country, it might have “serious consequences for the U.S.-Russian relationship.”

Snowden left Hong Kong “through a lawful and normal channel,” the city said in a statement. U.S. documents seeking Snowden’s arrest didn’t comply with legal requirements and there was thus “no legal basis to restrict Mr. Snowden from leaving Hong Kong,” the statement said.

Hong Kong’s decision and China’s protest escalate diplomatic tensions over Snowden, who went to Hong Kong a month ago, and the program that he claimed involved American hacking of Chinese and Hong Kong targets. China filed a protest over the program that Snowden brought to public light.

In a commentary yesterday, China’s official Xinhua News Agency reported that Snowden’s revelations demonstrate that the U.S. “has turned out to be the biggest villain in our age.”

“The U.S. government will be irate with their Hong Kong counterparts,” Simon Young, a law professor at the University of Hong Kong,’ said in an email. He said the U.S. “may even question whether Hong Kong government was acting in good faith pursuant to their treaty obligations.”

Hong Kong’s decision might allow it to avoid a confrontation with China, which took back sovereignty of the city from Britain in 1997 and can intervene in extraditions from the city if they relate to China’s defense or foreign affairs as well as the U.S.

“It’s a neat option from the Hong Kong government’s point of view, but there are also consequences,” Willy Wo-Lap Lam, a professor at the Chinese University of Hong Kong who specializes in Chinese politics, said in a phone interview. “The decision risks being judged as a pretext and not respecting the rule of law.”

The Associated Press contributed to this report.