The comment by parliamentarian Alexy Pushkov comes after U.S. Attorney General Eric Holder said Snowden would not get clemency if he came home, CNN reported.
Pushkov, head of the Foreign Affairs Committee of Russia's lower house, the Duma, said Snowden's year-old asylum would be extended and he wouldn't be sent back to the United States.
The legislator made his remarks during the World Economic Summit in Davos, Switzerland.
Holder said Thursday Snowden, who leaked secrets about U.S. and British intelligence gathering he collected while a contractor for the National Security Agency, could come home in a plea deal.
But clemency is out of the question, Holder said.
"We've always indicated ... that the notion of clemency isn't something that we were willing to consider," Holder said at the University of Virginia's Miller Center of Public Affairs.
"Instead, were he to come back to the United States to enter a plea, we would engage with his lawyers," he said.
"We'd do that with any defendant who wanted to enter a plea of guilty," Holder told the university's non-partisan research institute.
Holder did not indicate if he was open to engaging in negotiations with Snowden while he remained in Russia, beyond the reach of U.S. law enforcement.
President Obama told the New Yorker magazine last week he did not have "a yes/no answer on clemency for Edward Snowden."
"This is an active case, where charges have been brought," he said.
Snowden is charged with espionage and theft of government property.
Holder previewed his university remarks to MSNBC, saying the Justice Department would "engage in conversation" with Snowden, but clemency would be "going too far."
When asked if he considered Snowden a whistle-blower, Holder said: "I prefer the term defendant. That's the most apt title."
Snowden has never denied leaking the top-secret documents, but insisted his decision to provide them to the Washington Post, the Guardian and other newspapers was an act of conscience, intended to inform the public about the nature and breadth of NSA surveillance.
While Holder spoke at the University of Virginia Thursday, Snowden engaged in an online chat, saying he wanted to return to the United States to resolve his standoff but wouldn't do so until he knew he'd get a fair trial under revised whistle-blower protection laws.
The administration has insisted Snowden would receive a fair trial under the law.
"Returning to the U.S., I think, is the best resolution for the government, the public and myself, but it's unfortunately not possible in the face of current whistle-blower protection laws, which through a failure in law did not cover national security contractors like myself," Snowden said in the chat, which can be found at tinyurl.com/UPI-Snowden-chat.
Under the law he's charged with breaking, he couldn't argue in court he was acting in the public interest by revealing the NSA's surveillance programs, he said.
"This is especially frustrating, because it means there's no chance to have a fair trial, and no way I can come home and make my case to a jury," he said.
Snowden did not say in the chat if he would consider a plea bargain or negotiate any form of return to the United States.
Snowden said he wouldn't have released the NSA documents to the press if a whistle-blower process were in place for federal contractors.
"If we had had a real process in place, and reports of wrongdoing could be taken to real, independent arbiters rather than captured officials, I might not have had to sacrifice so much to do what at this point even the president seems to agree needed to be done," he said.
In June, he told the South China Morning Post in Bangkok he deliberately sought a position at contractor Booz Allen Hamilton Inc. with the intent of taking and leaking documents about NSA surveillance.
"My position with Booz Allen Hamilton granted me access to lists of machines all over the world the NSA hacked," he told the Post June 12. "That is why I accepted that position about three months ago."