– Canadian Prime Minister Justin Trudeau may have expected a lot to happen during the G-7 summit last weekend, but being condemned to an afterlife in both hell and heaven probably wasn't on the list.

"There's a special place in hell for any foreign leader that engages in bad-faith diplomacy with President Donald J. Trump and then tries to stab him in the back on the way out the door … And that's what bad-faith Justin Trudeau did with that stunt press conference," White House trade adviser Peter Navarro said during a Fox News interview Sunday.

The European Union responded to the attack on Sunday evening, with European Council President Donald Tusk tweeting that Trudeau deserved a "special place in heaven" for organizing the G-7 summit.

What caused the rift? Trump had already left the summit, and Trudeau gave a news conference in which he went to great lengths to not offend Trump. But Trudeau still said a few things that didn't go down well inside Air Force One.

Trudeau reiterated his objections to Trump's imposition of tariffs on steel and aluminum from Canada, Mexico and the European Union and his own plans to introduce retaliatory measures targeting U.S. products. "Canadians, we're polite, we're reasonable, but we also will not be pushed around," Trudeau said, triggering a dispute that currently revolves around three key issues.

In the two tweets that ended U.S. support for the joint G-7 statement, Trump accused Trudeau of having made "false statements" during a news conference. "PM Justin Trudeau of Canada acted so meek and mild during our G7 meetings only to give a news conference after I left saying that, 'US Tariffs were kind of insulting' and he 'will not be pushed around.' Very dishonest & weak," Trump wrote.

But French President Emmanuel Macron wrote of a united front of leaders against Trump, even though participants still described the talks as cordial, the Post reported.

Prior to Trump's pull-out, all G-7 nations agreed to a joint reaffirmation of "free, fair, and mutually beneficial trade and investment." The president later appeared to backtrack from his support, writing that "Fair Trade is now to be called Fool Trade if it is not Reciprocal."

Canadian farmers earn more per liter of milk because of that country's protectionist dairy industry. Canada argues that it still allows a higher ratio of sold milk to be imported from abroad than the U.S. does and that there is not necessarily a causal relationship between the U.S. industry crisis and tariffs.

Trump also indicated that he may soon target foreign cars produced for the U.S. market. The European Union targets U.S.-built cars with a 10-percent tariff, while the United States distinguishes between vans or pickup trucks and other cars. The former are targeted with a 25-percent tariff, while a 2.5 percent tariff applies on other vehicles.

European carmakers argue that they employ tens of thousands of U.S. workers and that any tariffs would result in U.S. layoffs.