Snowden, who was given refuge in Russia in 2013, is facing espionage charges in his home country U.S. for leaking documents about secret mass surveillance programs. He has been accused of spying for Russia — a claim both Snowden and Moscow have rebuffed.

The NSA leaker’s tweet came after NBC News, citing two senior U.S. officials, reported Friday that Russia is deliberating to hand over Snowden to “curry favor” with Trump, who has talked about establishing better relations with the country. The report added that a second intelligence community source supported the claims.

However, Snowden’s American Civil Liberties Union lawyer Ben Wizner said he does not know of any such plans by Russia as mentioned in the NBC News report.

“Team Snowden has received no such signals and has no new reason for concern,” he said.

In March 2016, during his presidential campaign, Trump said of Snowden: “I said he was a spy and we should get him back. And if Russia respected our country, they would have sent him back immediately, but he was a spy. It didn’t take me a long time to figure that one out.”

However, Russia rejected the allegations that Snowden was spying for the country.

According to former Deputy National Security Adviser Juan Zarate, Trump should be careful about any possible offer from Russia over Snowden.

“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,” Zarate said, according to NBC News.

“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 U.S. around the role of surveillance, the role of the U.S. 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,” Zarate