Former US spy agency contractor Edward Snowden has not yet formally accepted asylum in Venezuela, anti-secrecy group WikiLeaks said this evening.

A Russian politician earlier posted a statement to that effect on Twitter and then deleted it.

WikiLeaks, on its own Twitter feed, said that states involved in deciding an asylum destination for Mr Snowden, who fled the United States last month, "will make the announcement if and when the appropriate time comes".

Mr Snowden is wanted in the United States on espionage charges after revealing details of secret surveillance programmes.

He is believed to be in the transit area at a Moscow airport where he arrived on 23 June from Hong Kong.

Venezuelan President Nicolas Maduro said on Friday that he had decided to offer the 30-year-old American asylum.

Nicaragua and Bolivia also have said they would take in Mr Snowden, who has appealed to about 20 countries, including Ireland, for political asylum.

Alexei Pushkov, the pro-Kremlin chairman of the international affairs committee in Russia's lower house of parliament, tweeted that Mr Snowden had accepted Venezuela's asylum offer, but the tweet swiftly disappeared from his Twitter feed.

Mr Pushkov later tweeted that he had seen the news on state-run Russian television channel Rossiya-24, but a representative of Rossiya-24 said it had been referring to Mr Pushkov's initial tweet.

"Edward #Snowden has not yet formally accepted asylum in Venezuela," Wikileaks, whose British legal researcher Sarah Harrison is assisting Mr Snowden and travelled to Moscow with him, later said on Twitter.

Russian President Vladimir Putin has said Mr Snowden should choose a final destination and go there as soon as possible, but it is unclear how he would get to any of the Latin American countries that have offered him asylum.

Bolivia has accused Spain, France, Portugal and Italy of closing their skies to President Evo Morales' plane last week after being told it was carrying Mr Snowden from Moscow to Bolivia.

There are no direct commercial flights from Moscow to Venezuela, Nicaragua or Bolivia, and US authorities have urged nations around the world not to give Mr Snowden refuge.

"Mr Snowden ought to be returned to the United States where he is wanted on felony charges," White House spokesman Jay Carney said this evening, adding that "he should not be permitted to engage in further international travel beyond the travel necessary to return to the United States".