The father of fugitive whistleblower Edward Snowden said he turned down an FBI request to persuade his son to give himself up and praised Russian President Vladimir Putin for protecting him.

Lon Snowden said the FBI tried to enlist him to fly to Moscow's Sheremetyevo airport, where his son has been holed up since arriving from Hong Kong on June 23, and persuade the former NSA contractor to go back to the US where he is wanted on theft and espionage charges.

Despite being willing to go, Snowden Sr told The Washington Post he decided against the journey because US authorities had no idea they could actually get him in front of his son.

"I said, 'I want to be able to speak with my son. . . . Can you set up communications?' And it was, 'Well, we're not sure,'" he told the newspaper.

"I said, 'Wait a minute, folks, I'm not going to sit on the tarmac to be an emotional tool for you.'"

Edward Snowden went on the run after leaking documents that revealed the extensive snooping practices put in place by US and other countries' security agencies.

Lon said his son is not a traitor, but a patriot.

"As a father, it pains me what he did,'' he said. "I wish my son could have simply sat in Hawaii and taken the big paycheck, lived with his beautiful girlfriend and enjoyed paradise. But as an American citizen, I am absolutely thankful for what he did,'' he told the Post.

In a separate interview with Russia's Rossiya 24 state television, he thanked the Kremlin for the "courage and strength and conviction to keep my son safe."

Russia is considering an asylum request lodged by the NSA whistleblower.

Snowden also addressed his son and told him to find a safe haven, saying: "Edward, I hope you are watching this.

"Your family is well. We love you. We hope you are healthy, we hope you are well, I hope to see you soon, but most of all I want you to be safe. I want you to find a safe haven."