A former Mexican president is warning Canada that Donald Trump could turn his attention to the north next after spending the better part of his presidential campaign directing his ire at Mexico and its people.

"Canada please watch out, because today this guy goes crazy against Mexico and later he will do it with Canada," Vicente Fox said in an interview with Chris Hall on CBC Radio's The House. "If today is Mexico, next will be Canada, he will declare a trade war with Canada. That's a lose-lose proposition, everyone will lose with things like that. He's threatening NAFTA. That's absolutely stupid."

Trump has pilloried the free trade agreement between Canada, the United States and Mexico calling it "a disaster."

NAFTA, established in 1994, created a North American free trade bloc that eliminated most tariffs on trade between Canada, the U.S. and Mexico. Trump has said the deal has hollowed out the American heartland, shipping manufacturing jobs south to Mexico.

But the government of Canada says the agreement has been a boon to our economy.

"We estimate that 2.5 million Canadian jobs depend on trade with the United States," a spokesperson for International Trade Minister Chrystia Freeland said in a statement. "NAFTA has had an overwhelmingly positive effect on the Canadian economy. It has opened up new export opportunities, acted as a stimulus to build internationally competitive businesses, and helped attract significant foreign investment."

"We're being defrauded by all these countries," Trump said in a recent interview with the CBS News program 60 Minutes. "We need fair trade. Not free trade. We need fair trade. It's got to be fair," Trump insisted.

Fox said that Trump is dangerously misguided, threatening to destroy a trade deal that has generated millions of new jobs.

"He does not look at the results, he's just trying to please the U.S. electorate. Trading is a very positive economic issue that brings in development, jobs and wealth to the nations that trade. He is out of reality. I really consider him a danger. He cannot enclose that leading nation in four walls, that's stupid thinking, and it's based on fear," Fox said.

Fox was leader of the centre-right National Action Party and served as president of Mexico from 2000 to 2006. During his tenure he had close relations with former U.S. president George W. Bush and was a strong proponent of free trade among all of the North American countries.

He has gained international notoriety with his recent comments about Trump and the Republican presidential candidate's pledge to build a wall across the U.S. southern border. Trump has said he will force Mexico to pay for the wall.

The promise is at the heart of his campaign for president and has been turned into a call-and-response at his rallies, where he asks supporters who will pay for the wall and they yell back, "Mexico!"

"I have to say that we are not, I am not going to pay for that f***ing wall. And please don't take out the f***ing full word," Fox told Fusion TV's Jorge Ramos, speaking in English

FMR PRES of Mexico, Vicente Fox horribly used the F word when discussing the wall. He must apologize! If I did that there would be a uproar! —@realDonaldTrump

"This guy used a filthy, disgusting word on television, and he should be ashamed of himself and he should apologize, OK?" Trump said in response.

Trump a 'gringo'

The former Mexican leader said Canada and Mexico should band together and denounce Trump and his anti-trade policies that threaten our respective economies.

Former Mexican President Vicente Fox sends a message to Donald Trump. (@KApolitics / Twitter)

He also said Trump is reminiscent of American leaders from a previous generation who saw other nations not as partners, but as semi-colonial possessions to be used and abused at will.

"He more reminds me of the ugly American of the 20th century, the hated gringo in Mexico and Latin America. He represents that to me, that would be awful if we go back. Canada and Mexico are neighbours with them, and they should respect us as neighbours," he said.

NAFTA 'plus'

Fox said the upcoming Three Amigos summit — which will see U.S. President Barack Obama and Mexican President Enrique Peña Nieto travel to Ottawa to meet with Prime Minister Justin Trudeau — is a chance for the three countries to jump start relations after a period of some tension.

Former prime minister Stephen Harper slapped visas on Mexican travellers headed for Canada in an effort to eliminate bogus refugee claims, a move that angered Mexican politicians and soured bilateral relations. Harper postponed a scheduled Three Amigos summit last winter.

"I think we need a NAFTA plus. We should work on climate, we should on natural resources, we should work on an [integrated] financial system that is all comprehensive between our two, three nations," Fox said. "I think we need a NAFTA that brings in new and refreshing ideas. This initiative called upon by Prime Minister Justin Trudeau, I think it's exciting but the thing is to make it come true."

Trudeau has vowed to lift the visa requirement, and has pushed for a North American climate deal to tackle greenhouse gas emissions.