Edward Snowden possesses data that could prove far more "damaging" to the US government but the fugitive leaker has chosen not to release them, said a journalist who first broke the story.
Glenn Greenwald told Argentina's La Nacion paper that Snowden, who is currently stranded in Moscow, had only sought to alert people that information they thought was private was being exploited by US intelligence agencies.
"Snowden has enough information to cause more damage to the US government in a minute alone than anyone else has ever had in the history of the United States," he told the paper in an interview published yesterday.
"But that's not his goal," said Greenwald, who published a series of stories in Britain's Guardian newspaper based on top-secret documents about sweeping US surveillance programmes that were leaked by Snowden.
His comments came as Russia waited today for a promised request for asylum from Snowden.
The United States wants the former National Security Agency (NSA) contractor returned to them to face trial over the leaks. Moscow has so far rejected that demand.
Snowden, 30, has been stranded in the transit zone of Moscow's Sheremetyevo airport, after the US withdrew his passport on his arrival from Hong Kong three weeks ago.
Snowden on Friday dramatically summoned Russian activists to his temporary base, to say he wanted to claim asylum in Russia until he could safely travel to Latin America for a permanent sanctuary.
He withdrew an initial request earlier this month after Russian President Vladimir Putin said he would have to stop releasing information embarrassing to Washington if he wanted to stay.
After Snowden made his statement Amnesty International reiterated its support for him and denounced what it described as US government persecution of him.
Human Rights Watch accused Washington of trying to block Snowden's attempts to claim asylum and said that was in violation of his rights under international law.
Representatives from both organisations attended Snowden's presentation.
But on Saturday, officials in Moscow said they were still waiting for Snowden's request.
Foreign Minister Sergei Lavrov said Snowden would have to submit his application to the Federal Migration Service (FMS), Russian news agencies reported.
The head of Russia's Federal Migration Service (FMS) Konstantin Romodanovsky said yesterday they had received nothing. If they did, he added, it would examined according to the usual procedures.