Ex-National Security Agency contractor Edward Snowden has asked for asylum in Ecuador, the South American country's foreign ministry announced Sunday as the United States urged countries to rebuff the leaker.

Snowden's story took a dramatic turn Sunday when he flew from Hong Kong to Moscow, aided by the international anti-secrecy group WikiLeaks. The group reported that Snowden had touched down in Moscow, and CNN spotted a car with diplomatic plates and an Ecuadorian flag at Moscow's international airport.

But WikiLeaks, which facilitates the publication of classified information and says it's helping Snowden, did not disclose what country would be his final destination.

The United States is asking Cuba, Ecuador and Venezuela not to let in Edward Snowden, who leaked information about NSA surveillance programs, a senior administration official told CNN on Sunday. The United States also is asking those countries - rumored to be possible final destinations for Snowden - to expel him if they do admit him, the official said.

Snowden took off not long after the United States asked Hong Kong to extradite the former National Security Agency contractor on espionage charges. The Reuters news agency reported that Ecuadorian Ambassador Patricio Alberto Chavez Zavala said he was entering a Moscow airport hotel to talk to Snowden.

Word of Snowden's travels touched off widespread speculation about the former NSA contractor's next steps. Some media reports suggested that he could be traveling to Ecuador, Venezuela or Cuba. Some passengers at the airport said it appeared he was whisked away in a diplomatic car. Other reports said he might spend the night in an embassy in Moscow or at an airport hotel. But no one - or at least no one speaking out publicly on Sunday - could say for sure exactly where Snowden was or where he will go next.

The global guessing game has placed WikiLeaks in the international spotlight once again, as the organization revealed in a series of online posts that it was helping Snowden leave Hong Kong and seek "political asylum in a democratic country." Baltasar Garzon, a former Spanish judge and the organization's legal director, said in a statement Sunday that the treatment of Snowden has been "an assault against the people."

"The WikiLeaks legal team and I are interested in preserving Mr. Snowden's rights and protecting him as a person," he said.

Snowden, who leaked top-secret details about US surveillance programs, left Hong Kong on Sunday "through a lawful and normal channel," the Hong Kong government said.

In a statement Sunday, Justice Department spokeswoman Nanda Chitre said Hong Kong authorities had informed US officials of Snowden's departure. "We will 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," she said.

The US government had also asked Hong Kong to issue a provisional arrest warrant for Snowden, the Hong Kong Special Administrative Region said in a statement. But HKSAR officials said there were problems with the request. "Since the documents provided by the US government did not fully comply with the legal requirements under Hong Kong law, the HKSAR government has requested the US government to provide additional information," Hong Kong officials said.

Because Hong Kong didn't have enough information, "there is no legal basis to restrict Mr. Snowden from leaving Hong Kong," the government said.

A Justice Department official said Sunday that the United States had met requirements with its request, disputing the assertion from authorities in Hong Kong. "They came back to us with a few questions late Friday and we were in the process of answering those questions," the official said. "We believe we were meeting those requirements. As far as the relationship with Hong Kong goes, this raises questions and we will continue to discuss with authorities there."

Hong Kong's lack of intervention came after Snowden told the South China Morning Post that US intelligence agents have been hacking computer networks in Hong Kong and mainland China for years. Hong Kong said it wanted to have some words with the United States about that.

"The HKSAR government has formally written to the US government requesting clarification on earlier reports about the hacking of computer systems in Hong Kong by US government agencies," Hong Kong officials said in the same statement. "The HKSAR government will continue to follow up on the matter so as to protect the legal rights of the people of Hong Kong."