Journalists stand next to the Ecuador ambassador's car while waiting for the arrival of Edward Snowden at Sheremetyevo airport just outside Moscow (AP)

The former National Security Agency contractor wanted for revealing classified secrets is seeking asylum in the South American country of Ecuador, Foreign Minister Ricardo Patino has said.

The anti-secrecy group WikiLeaks also announced that Edward Snowden "is bound for the Republic of Ecuador via a safe route for the purposes of asylum, and is being escorted by diplomats and legal advisers from WikiLeaks".

The organisation's founder Julian Assange was granted asylum by Ecuador last year and has been staying at the country's embassy in the UK.

Mr Snowden was on an Aeroflot flight from Hong Kong that arrived in Moscow on Sunday and was booked on a flight to Cuba on Monday, the Russian news agencies ITAR-Tass and Interfax reported, citing unnamed airline officials.

Mr Snowden had been in hiding in Hong Kong for several weeks after he revealed information on the highly-classified spy programmes. WikiLeaks said it was providing legal help to Mr Snowden at his request and that he was being escorted by diplomats and legal advisers from the group.

Mr Assange has spent a year inside the Ecuadorean embassy in London to avoid extradition to Sweden to face questioning about sex crime allegations. He told the Sydney Morning Herald that his organisation is in a position to help because it has expertise in international asylum and extradition law.

A US official said Mr Snowden's passport was annulled before he left Hong Kong for Russia.

His travel plans could be complicated - but not thwarted - by lack of a passport. The US official said that if a senior official in a country or airline ordered it, a country could overlook the withdrawn passport.

PA Media