Former U.S. presidential candidate Donald Trump has suggested whistleblower Edward Snowden, who is wanted in the United States on espionage charges, should be executed.

The billionaire real estate tycoon also called Snowden a spy.

“You know, spies in the old days used to be executed,” Trump said in an interview with Fox News. “This guy is becoming a hero in some circles. Now, I will say, with the passage of time, even people that were sort of liking him and were trying to go on his side are maybe dropping out.”

“We have to get him back and we have to get him back fast. It could take months or it could take years, and that would be pathetic,” the business magnate added.

Snowden admitted that he leaked top secret information about the U.S. government’s surveillance programs. He left Hong Kong for Russia on Sunday to seek asylum in another country.