On Saturday, former Mexican President Felipe Calderon slammed Republican presidential front runner Donald Trump, ridiculing the real estate mogul’s “stupid wall.”

Mocking Trump as a “not very well informed man,” Calderon told CNBC, "Mexican people, we are not going to pay any single cent for such a stupid wall! And it's going to be completely useless.”

In an unmistakably irate tone, Calderon then clamored:

The first loser of such a policy would be the United States."If this guy pretends that closing the borders to anywhere either for trade (or) for people is going to provide prosperity to the United States, he is completely crazy.

Mexico’s former president couldn’t help but also chime in on the American electorate. "It is incredible that a quite admirable society like the American society could produce such kind of candidates," Calderon opined. "I cannot understand that. No offense, no offense to America. So Donald Trump … is ambitious but not exactly [a] very well-informed man. I don't want to say ignorant, but he is not very well informed."

Calderon served as President of Mexico from 2006 to 2012 when he was replaced by a more charismatic Enrique Peña Nieto of the Industrial Revolutionary Party. He has kept a relatively low profile since.

In typical Trumpian fashion, the real magnate shot back at Calderon at a rally in Manchester, New Hampshire on Monday night. Trump doubled-down on his plans to build a wall, claiming that Calderon’s criticism only makes him want to build a bigger wall.

"The head of Mexico today said, 'There's no way we're gonna pay for that wall, please inform Mr. Trump,'" Trump shouted. "I said the wall's just gonna get bigger when he has that attitude.”