Edward Snowden's recently-granted Russian citizenship may expose the former US National Security Agency (NSA) contractor to conscription in to Russia's military, the US said on Monday.

State Department spokesman Ned Price said Snowden "makes him subject to any Russian decrees that may come down, including the one we heard about last week." He was likely alluding to Russian President Vladimir Putin's decision to call up 300,000 Russian reservists to bolster his flagging war effort in Ukraine.

"Mr. Snowden is apparently now a Russian citizen," Price told reporters. "The only thing that has changed is that as a result of his Russian citizenship, apparently now he may well be conscripted to fight in a reckless war in Ukraine."

Price reiterated the US position that Snowden, who publicly unveiled secretive mass surveillance programs run by the NSA during the Obama administration in 2013, should return to his home country "where he should face justice."

Snowden's disclosures stunned the US, and the global public, setting off a series of diplomatic crises after some of his disclosures brought to light sensitive programs used to surveil some of the US's closet allies.

Former President Barack Obama condemned Snowden’s actions even after his former top lawyer, Eric Holder, acknowledged Snowden provided a "public service."

Snowden was granted asylum by Russia in 2013 after he was charged with espionage. Putin signed a decree on Monday granting him full Russian citizenship.