(AP Photo/Gerald Herbert)
This photo is from 2012, when Donald Trump thought better of Mitt Romney and endorsed him.
Former Republican presidential nominee Mitt Romney drew an angry response Sunday from current GOP front-runner Donald Trump.
In an interview on CNN on Sunday, the former Republican presidential candidate said he will back the eventual Republican nominee for president. But he seemingly refused to entertain the idea that Trump could be the nominee.
"Well, I don't think it's likely that Donald Trump will be the nominee, but it's obviously too early to tell. At this stage numbers go up and down, candidates have bursts of support," Romney told "State of the Union" host Jake Tapper.
"Donald Trump has had a lot of support for a long time, and so I think a lot of folks think, 'Well, this could [go] a lot further than, than people had expected.'"
Romney's comments Sunday came after he hammered Trump earlier this weak during an appearance on the podcast hosted by former Obama senior adviser David Axelrod.
"I think Donald Trump has said a number of things which are hurtful — and he has said that they were 'childish' in some respects — and I think [they] will be potentially problematic either in the primary or a general election," Romney told Axelrod.
"And they relate to things he's said about women, and things he's said about members of the news media, things he's said about Hispanics," he added. "I think he'll have some challenges if he proceeds to the next stage."
Despite numerous predictions of his demise, Trump still currently leads the presidential Republican field.
As he often does, Trump responded to Romney almost instantly on Twitter, attacking him over several of Romney's high-profile gaffes during the 2012 presidential race.
Though Trump flirted with a presidential bid in the 2012 cycle, he ultimately endorsed Romney. Since announcing his candidacy earlier this summer, however, Trump has soured on Romney, frequently criticizing the former governor on Twitter.