A full-blown trade war between the U.S. and Canada could lead to a recession in both countries, economist says.

Trump has threatened to impose tariffs on products from Canada and Mexico if the countries don’t stop what he called the flow of drugs and migrants across southern and northern borders.

U.S. President-elect Donald Trump said on Saturday he had a "very productive" meeting with Canadian Prime Minister Justin Trudeau in which they discussed border-related issues and other topics including trade,