Former Massachusetts Gov. Mitt Romney (R) ratcheted up his criticism of real-estate magnate Donald Trump in a new interview released Friday.

Romney, the Republican 2012 presidential nominee, discussed Trump during a wide-ranging interview with David Axelrod, who as President Barack Obama’s top campaign adviser helped defeat Romney three years ago.

“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 said.

“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.”