Snowden was stranded in a Moscow airport last year en route from Hong Kong to Cuba, shortly after he revealed the NSA's sprawling programme of tapping phones.
He received temporary asylum in Russia, attracting Washington's ire. Under Russian law, that status must be renewed annually. Snowden's lawyer, Anatoly Kucherena, was quoted by the state news agency RIA Novosti on Thursday as saying he expected a decision soon on the application and that Snowden could stay at least until the decision is made.