The former intelligence contractor has spent three years in exile in Russia after initiating the largest data leaks in US history, fuelling a firestorm over the issue of mass surveillance.
"If not for these disclosures, if not for these revelations, we would be worse off," he told Britain's Guardian newspaper in a video-link interview from Moscow yesterday.
"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.
Snowden, whose residency permit in Russia runs out next year, explained he was prepared to spend time in jail in the US, adding he was "willing to make a lot of sacrifices for my country".
US anti-establishment director Oliver Stone called for Obama to pardon Snowden while unveiling his espionage thriller biopic about the whistleblower at the Toronto film festival earlier this month.
Last year, the White House rejected a petition signed by over 150,000 urging a pardon for Snowden, saying he should be "judged by a jury of his peers".