"He reiterated our belief that Mr Snowden needs to be returned to the United States where he will face a fair trial," state department spokeswoman Jen Psaki said.
"Any move that would allow him to leave the airport would be deeply disappointing," she told reporters.
Earlier, White House press secretary Jay Carney had told reporters aboard Air Force One: "We're seeking clarity from Russian authorities about Mr Snowden's status and any change in it."
"He has been charged with serious felonies for the unauthorised leaking of highly classified information," he said.
"Mr Snowden should be expelled and returned to the United States," Carney said.
He spoke amid conflicting reports from Moscow about whether Snowden would be allowed to leave the transit area of Moscow's Sheremetyevo Airport.
Snowden has been marooned at the airport amid an international tug of war set off by his revelations about highly secret US electronic surveillance programmes.
Russian news reports said he had been given a document allowing the former IT contractor to leave the transit area and cross the Russian border, but a lawyer who has been helping him denied that.