Vicente Fox is becoming better known to the world as a Trump-baiter than he was in his former position as president of Mexico.
Former Mexican President Vicente Fox ripped President TrumpDonald John TrumpHouse Democrat slams Donald Trump Jr. for "serious case of amnesia" after testimony Skier Lindsey Vonn: I don't want to represent Trump at Olympics Poll: 4 in 10 Republicans think senior Trump advisers had improper dealings with Russia MORE on Twitter on Thursday evening for reportedly referring to Haiti, El Salvador and some African nations as "shithole countries" in an Oval Office meeting.
"Your mouth is the foulest shithole in the world", Fox tweeted at Trump. "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?"
Fox made the comments after Trump's remark about American taking people from "shithole countries" went public.
Vicente Fox, a former Mexican President, who served from 2000-2006 and a successful ex-top manager of Coca-Cola Mexico, has given a withering response to these words, attributed to the USA president.
He began feuding with Trump back when the USA president was still on the campaign trail.
His colourful language sparked a request from Trump to apologise, which Fox robustly ignored, and a trending hashtag of #f--ingwall.