Former Mexican President Vicente Fox had some harsh words for President Trump after he reportedly referred to Haiti, El Salvador, and African nations as "shithole countries" during a meeting with lawmakers.

".@realDonaldTrump, your mouth is the foulest shithole in the world," Fox tweeted in response on Thursday. "With what authority do you proclaim who's welcome in America and who's not. America's greatness is built on diversity, or have you forgotten your immigrant background, Donald?"