It has been reported that Russia is considering sending Edward Snowden back to the United States as a 'gift' to President Donald Trump, and the NSA whistle-blower appears to be thrilled.

Trump has called the him a 'spy' and a 'traitor' who deserves to be executed, reported the Huffington Post.

Snowden, however, tweeted: 'Finally: Irrefutable evidence that I never cooperated with Russian Intel. No country trades away spies.'

The upbeat tone is understandably surprising, as he faces a future in prison for treason charges after leaking thousands of pages of classified documents in 2013, uncovering NSA's massive surveillance programs.

A Snowden handover is an attempt for Russia President Vladimir Putin to 'curry favor' with Trump, a senior US official with knowledge of sensitive Russian intelligence information told NBC News on Friday.

Russia is considering sending Edward Snowden back to the United States as a 'gift' to President Donald Trump

In response to the news, Snowden tweeted: 'Finally: Irrefutable evidence that I never cooperated with Russian Intel. No country trades away spies'

The Trump administration should be cautious in accepting any Snowden offer from Putin, said former deputy national security adviser Juan Zarate.

'For Russia, this would be a win-win. They've already extracted what they needed from Edward Snowden in terms of information and they've certainly used him to beat the United States over the head in terms of its surveillance and cyber activity', said Zarate.

'It would signal warmer relations and some desire for greater cooperation with the new administration, but it would also no doubt stoke controversies and cases in the US around the role of surveillance, the role of the US intelligence community, and the future of privacy and civil liberties in an American context.

'All of that would perhaps be music to the ears of Putin'.

Trump has called the whistleblower a 'spy' and a 'traitor' who deserves to be executed

The White House didn't comment on the report, but the Justice Department told NBC News it would welcome the return of Snowden, who has been charged under the Espionage Act and could face decades in prison.

Snowden was working as a contractor at a National Security Agency facility in Hawaii when he leaked a trove of documents to journalists in 2013 that exposed widespread surveillance on ordinary Americans through the bulk collection of metadata.

He fled to and was granted asylum in Moscow. His residency permit was recently extended until 2020, which could make him eligible to apply for Russian citizenship, officials say.

He had a similar reaction to that on Twitter when he was ionterviewed with Yahoo News in December. He smiled, and even laughed, saying: 'I'm actually kind of encouraged. IT wasn't so many years ago that people said "this guy's a Russian spy." But countries don't give up their spies'.

However he did say that it would not be something he wanted to happen, saying: 'That would obviously be something that would be a threat to my liberty and to my life'.

Trump and CIA Director Mike Pompeo have condemned Snowden in the strongest terms.

'I think he's a total traitor and I would deal with him harshly', said Trump in July.

'And if I were president, Putin would give him over'.

The Trump administration should be cautious in accepting any Snowden offer from Russian President Vladimir Putin, said former deputy national security adviser Juan Zarate

Snowden live tweeted in a December interview that being forced to return to the US would violate his human rights

In October 2013, Trump tweeted: 'Snowden is a spy who should be executed'.

Pompeo concurred last February: 'I think the proper outcome would be that he would be given a death sentence'.

In a December interview live streamed on Twitter, Snowden said being forced to return to the US would be a human-rights violation.

'A lot of people have asked me: Is there going to be some kind of deal where Trump says, "Hey look, give this guy to me as some kind of present"? Will I be sent back to the US, where I'll be facing a show trial?' said Snowden.

'Is this going to happen? I don't know. Could it happen? Sure. Am I worried about it? Not really, because here's the thing: I am very comfortable with the decisions that I've made. I know I did the right thing'.

Snowden's Russian lawyer, Anatoly Kucherena, told Russian news agency RIA Novosti that Snowden wants to return to the US without the fear of arrest.

'We hope very much that the new U.S. president would show some weighted approach to the issue and make the one and only correct decision — to stop prosecution against Edward Snowden', Kucherena said.

There's no way to predict if Putin will hand Snowden over to Trump, Zarate said.

Snowden has said he would be willing to return if he could be guaranteed a fair trial, reported the Huffington Post.