Edward Snowden infuriated American officials by leaking details of the NSA's globe-spanning spy programmes and has been on the run since leaving Hong Kong over the weekend.
Russian President Vladimir Putin says Snowden is in the transit zone of Moscow's Sheremetyevo Airport and has rejected US pleas to turn him over.
WikiLeaks, which says it is helping Snowden seek asylum, has declined to reveal details about Snowden's plans, citing security concerns. The group did not return messages today.