HANOI (AFP) - Ecuador's foreign minister said Monday his country was "analysing" a request for asylum by fugitive US intelligence leaker Edward Snowden who is currently in Moscow.

"We will make a decision... we are analysing it," Foreign Minister Ricardo Patino told reporters in Hanoi of the request by Snowden who is on the run from US authorities over his explosive leaks on American intelligence methods.

Snowden fled Hong Kong for Moscow on Sunday and was believed to be in the transit area of Moscow's Sheremetyevo airport.

"It (the request) has to do with freedom of expression and the security of citizens around the world. We always act by principle not in our own interest. There are some governments who act more on their own interests, we do not," he added.

Snowden, a former National Security Agency (NSA) contractor, arrived in Russia on Sunday from Hong Kong, hoping to win asylum in Ecuador and evade arrest after leaking sensational details of secret US surveillance programmes. He was expected to head to Ecuador via Cuba and AFP correspondents at Moscow's Sheremetyevo airport saw an Ecuadoran flagged diplomatic car at VIP arrivals.

"We know he is in Moscow, we're in talks with higher authorities," Mr Patino, who is on an official visit to communist Vietnam, said. The South American country, led by outspoken leftist President Rafael Correa, has been sheltering WikiLeaks founder Julian Assange, who is wanted by Sweden, at its London embassy for the past year.

US authorities have been severely embarrassed by Snowden's revelations of intelligence trawling by the NSA of phone call logs and Internet data, prompting concern from governments around the world and outrage from privacy campaigners.

Snowden made the revelations from Hong Kong which allowed him to travel to Moscow, prompting criticism from US authorities have laid charges including of theft and espionage against the whistleblower.