Hafthor Julius Bjornsson, the man known to "Game of Thrones" fans as "The Mountain" and the reigning World's Strongest Man, says he is willing to do whatever is necessary to win -- including taking steroids.

In a lengthy interview with ESPN's E:60, Bjornsson was asked whether he had ever taken steroids, long associated with the sport of strongman. "Yes, I have," Bjornsson says in the 2017 interview, which aired Sunday morning on E:60. "When you want to be the best, you do whatever it takes."

Bjornsson did not elaborate on when he has used performance-enhancing drugs. Asked how often he takes steroids and if he's still doing it, Bjornsson deferred: "Can we just skip those questions?"

The annual World's Strongest Man (WSM) competition officially prohibits the use of PEDs, but it is not clear the extent or effectiveness of its drug testing for its athletes.

Bjornsson, 30, turned to competing in strongman events after his dream of becoming a professional basketball player ended when he twice broke his right ankle at the age of 19. Turning to weightlifting, the now 6-foot-9, 440-pound native of Iceland was discovered in a gym by countryman Magnus ver Magnusson, a four-time winner of the WSM competition.

In a few short years, Bjornsson was competing, and in 2011 he claimed the title of Iceland's Strongest Man. In September of that year, he entered WSM for the first time, finishing sixth in the competition held in North Carolina and won by American Brian Shaw. But that was the last time he finished out of the top three.

From 2012 to 2017, Bjornsson -- who says he eats eight meals a day when training -- chalked up three second-place and three third-place finishes. What he calls "probably my hardest loss" came in 2017, when he fell one point short of the United Kingdom's Eddie Hall.

Bjornsson, who says he has never failed a drug test during competition, finally earned the right to be called World's Strongest Man when he finished on top last May in the Philippines.

Hafthor Bjornsson, seen here during the World Strongest Man competition in 2013, says he has used steroids as he strove to "be the best." Victor Fraile/Getty Images

Along the way, Bjornsson was approached by representatives of "Game of Thrones," who were filming in Iceland, and since Season 4 has played towering villain Gregor "The Mountain" Clegane. That role has earned him worldwide notoriety and invitations to work in commercials and appear at other events, such as stirring up fans at a Minnesota Vikings game.

Steroid use has often been blamed in the premature deaths of strongman competitors, including another four-time world champion from Iceland, Jon Pall Sigmarsson. His death in 1993, at the age of 32 while training, was reported to be from cardiac arrest with anabolic steroids as a contributing factor.

Bjornsson admits all the roles he juggles in his life -- athlete, actor, pitchman, father -- have put a strain on him, and his family says they fear for his health.

"When you are putting yourself through all this," says Bjornsson, "I've always thought about, 'What if I pass away?' It would be very hard to know that I left my family too soon. I want to be there for my family. I want to be there for my daughter. But this is my life. This is what I enjoy to do."

This year's World's Strongest Man competition is scheduled for June 13-16 in Bradenton, Florida. Bjornsson said he plans to be there to defend his title.