Russian President Vladimir Putin has said a former US spy agency contractor is in the transit area of Moscow's Sheremetyevo airport, was free to leave and should do so as soon as possible.

Edward Snowden, charged with disclosing secret US surveillance programmes, left Hong Kong for Moscow on Sunday.

Mr Putin told a news conference during a visit to Finland he hoped the affair would not affect relations with Washington, which wants Russia to send him to the US, but indicated Moscow would not hand him over.

Mr Putin said: "We can only hand over foreign citizens to countries with which we have an appropriate international agreement on the extradition of criminals," adding that Mr Snowden has committed no crime in Russia.

Mr Putin dismissed US accusations against Moscow over the case as "ravings and rubbish", saying Russian security agencies had not worked with Mr Snowden but added that he hoped the affair would not hurt relations with the US.

The US State Department said diplomats and Justice Department officials were talking to Russia, suggesting they sought a deal to secure his return to face espionage charges.

"Mr Snowden is a free person," Mr Putin said of the 30-year-old American, who is being aided by the anti-secrecy group Wikileaks and has asked Ecuador for political asylum. "The sooner he chooses his final destination, the better it would be for us and for himself."

US officials criticised Beijing and Moscow for allowing Mr Snowden to escape their clutches but US partners on the UN Security Council, already at odds with Washington over the conflict in Syria, hit back yesterday.

Foreign Ministry spokeswoman Hua Chunying said in Beijing: "The United States' criticism of China's central government is baseless. China absolutely cannot accept it."

US Secretary of State John Kerry said yesterday there was no need to raise the level of confrontation with Russia over Mr Snowden. Speaking at a news conference in Jeddah, Saudi Arabia, Mr Kerry added he hoped Russia would not see its interests in siding with a fugitive from justice.

Journalists camped out at the airport have not seen Mr Snowden and say a heavy security presence has been relaxed for the past 24 hours. Mr Snowden has not registered at a hotel in the transit zone, hotel sources say.

He is travelling on a refugee document of passage provided by Ecuador, the anti-secrecy group WikiLeaks said.

Ecuador, like Cuba and Venezuela, is a member of the Alba bloc, an alliance of leftist governments in Latin America that pride themselves on their anti-imperialist credentials. The Quito government has been sheltering WikiLeaks founder Julian Assange at its London embassy for the past year.

An airport source confirmed Mr Snowden was travelling with Sarah Harrison, a legal researcher working for WikiLeaks.

US President Barack Obama said earlier this week his government was "following all the appropriate legal channels working with various other countries to make sure the rule of law is observed".

But US officials said intelligence agencies were concerned they did not know how much sensitive material Mr Snowden had in his possession and he may have taken more documents than estimated.