0237 GMT October 16, 2019
Snowden, who lives in Moscow, appeared via video link on Wednesday at a New York press conference, where advocates from human rights groups called for a pardon.
The campaign started an online petition, at pardonsnowden.org, urging Obama to give him amnesty before his term ends in January.
"Edward Snowden's case presents one for President Obama to use the presidential power of pardon proudly and unequivocally, in recognition of one of the most important acts of whistleblowing in modern history," said Anthony Romero, the executive director of the American Civil Liberties Union (ACLU).
However, the chances of a pardon appear slim for Snowden as a similar initiative was launched in July, in which the White House rejected a petition to pardon Snowden that had garnered more than 160,000 signatures.
The launch of campaign came after the release of the Oliver Stone film "Snowden," which his supporters hope will rally support behind the whistleblower.
During the video conference, Snowden reiterated that he could not receive a fair trial in the United States under the Espionage Act.
"It does not permit a whistleblower defense," he said. "The law does not distinguish between those who give free sensitive information to journalists and spies who sell it to foreign powers."
"I'm comfortable with the decisions I made. But I don't think it's up for me to decide the direction of the future of our society. I believe that that's a participatory multilateral decision and we should intentionally try to remove the outsize influence of a particular individual, and that includes myself, and that's why I do not myself ask for pardon and I never will."
Conversely, Snowden implied on Tuesday that he pursues pardon, The Guardian reported. He argued that it had been morally "necessary" to shine a light on mass surveillance.
"Yes, there are laws on the books that say one thing, but that is perhaps why the pardon power exists -- for the exceptions, for the things that may seem unlawful in letters on a page but when we look at them morally, when we look at them ethically, when we look at the results, it seems these were necessary things," he said.
The US authorities charged Snowden with espionage and theft of state secrets in documents he gave journalists Glenn Greenwald, Laura Poitras and Ewen MacAskill. He faces up to 30 years in prison.
Snowden leaked thousands of classified intelligence documents in June 2013, revealing the extent of the NSA’s spying activities, including the massive collections of phone records of Americans and foreign nationals as well as political leaders around the world. His asylum in Moscow has been a source of tension between the US and Russia, with the US president canceling a planned meeting with Russian President Vladimir Putin at the G20 Summit in 2013 after Russia agreed to to let him in.