Former GOP presidential candidate Mitt Romney has repeatedly insisted that he is not planning a White House run in 2016, but in an interview Tuesday, he acknowledged that "circumstances could change," Politico reported.

In an interview on the nationally syndicated radio program "The Hugh Hewitt Show," the former Massachusetts Gov. told radio host Hugh Hewitt that "circumstances can change," but he still stood by his belief that a better candidate can do the job. "Circumstances can change, but I'm just not going to let my head go there," the 2012 Republican presidential nominee told Hewitt. "I had the chance of running. I didn't win. Someone else has a better chance than I do. And that's what we believe, and that's why I'm not running."

When Hewitt questioned Romney whether he would run if he knew he was the only viable candidate to beat former Secretary of State Hillary Clinton, who also has not declared her candidacy for president, he said a possible GOP contender "not defined yet" and "perhaps ... from the next generation" would be a better bet. "Had I believed I would actually be best positioned to beat Hillary Clinton, then I would be running."

"I'm expecting someone to be able to catch fire and get the job done," Romney added.

When further pressed about running again for the GOP nomination, Romney referenced a scene from the movie "Dumb and Dumber," saying the chance he'd run is "one of a million," according to Politico. "Let's say all the guys that were running all came together and said, 'Hey, we've decided we can't do it, you must do it.' That's the one of a million we're thinking about," Romney said.

Despite Romney's insistence, his former running mate, Wisconsin Rep. Paul Ryan, has said that he wishes the former Massachusetts governor would take another shot at the White House, Huffington Post reported. "I sure wish he would," Ryan said Sunday on CBS' "Face the Nation." "I think he'd make a phenomenal president. He has the intellect, the honor, the character and the temperament to be a fantastic president. ... But he keeps saying that he's not going to run."

Following his loss to President Obama in 2012, most pundits believed that Romney's political career was over. "But a sympathetic portrayal in a Netflix documentary, entitled 'Mitt,' combined with his fund-raising for midterm candidates in the 2014 elections, has generated considerable buzz," CNN reported.