Edward Snowden (Glenn Greenwald/Laura Poitras via Guardian)

NSA whistleblower Edward Snowden has decided to stick around in Russia for a little longer — provided authorities there are willing to keep thumbing their nose at the United States' entreaties to ship him home to face trial on charges of exposing intelligence secrets.

Snowden's Russian attorney, Anatoly Kucherena, told Russian media on Wednesday that he and his client "have submitted documents for extending his stay in Russia" past when his temporary asylum is set to expire July 31.

The Russian government granted Snowden asylum for a year last summer after he became stranded in a Moscow airport trying to fly from Hong Kong to Cuba. U.S. officials had revoked his passport and charged him with espionage and theft of government property — he could face up to 10 years in prison for each crime.

Snowden gained international attention when he used his top-secret security clearance to obtain and leak classified documents detailing the inner workings of the U.S. intelligence community to the news media. His revelations were first published in The Washington Post and in Britain's Guardian newspaper.

The revelations have shed light on secret U.S. government operations, including data mining and global Internet surveillance. But in that time, the United States has not been able to apprehend Snowden or even pin down much information about him — including some of the most basic facts about his existence.

A recent Post investigation by Greg Miller revealed that the United States still doesn't know exactly where Snowden lives in Russia or how much regular contact he has with the Russian security services.

Despite high-level coordination among U.S. intelligence agencies, Miller's investigation showed, U.S. efforts remain largely dependent on Russia either slipping up or showing its hand. Without Russian cooperation, the United States has limited abilities to trace Snowden in and around Moscow, and unless the United States can show that Snowden is colluding with Russian authorities, it will be difficult to substantiate the most serious charges against him. There has been no determination that he is an “agent of a foreign power,” a legal distinction required to make an American citizen a target of espionage overseas.

Snowden has maintained throughout his asylum that he has not cooperated with foreign authorities or passed any classified U.S. information on to them.

But that doesn’t mean Russia will decide to cooperate with U.S. requests to send him home.

Since Snowden procured his protected status, the relationship between the United States and Russia has significantly worsened.

In the weeks after Snowden’s arrival in Russia, President Obama skipped a planned meeting with Russian President Vladimir Putin. In the ensuing months, tense relations over the fighting in Syria gave way to an open standoff between the two global powers over Russia’s involvement in Ukraine’s conflict and its annexation of that country’s autonomous Crimea region. Since then, the United States has also led efforts to impose sanctions on Russia and excise the country from the Group of Eight.

In various interviews with the news media, Snowden has spoken highly of Russia and how he has been treated there — though he did indicate to one Brazilian television program that he would be happy to accept asylum in Brazil as well. Snowden has also maintained that he would face an unfair trial if returned to the United States — and, thus, cannot go home.

U.S. and Russian officials were expecting that Snowden would seek to renew his asylum as the expiration date approached. Kucherena would not say whether his client had applied for a simple extension of his asylum or some other status.