But economic, political and technological changes have left Canada with few ways to handle trade restrictions now.

Ottawa is ready to retaliate if U.S. president-elect Donald Trump slaps Canada with devastating tariffs, Prime Minister Justin Trudeau promised Friday — and his ministers say Republicans in Washington don't fully understand the likely impact of the duties on both countries' economies.

The president-elect’s vow to impose 25 percent duties on Canadian imports could ravage Canada’s auto industry and decimate Windsor, a city deeply tied to the U.S.

President-elect Donald Trump's threatened tariffs could prompt Canada to pursue dollar-to-dollar retaliation or an export tax on oil and gas bound for the U.S.