"If the United States escalates, I will not hesitate to shut the electricity off completely," Doug Ford said Monday.

President Trump imposed tariffs on imports from Canada, Mexico, and China as part of his "America First" agenda. Canada, Mexico, and China have retaliated with their own tariffs on U.S. goods. Economists warn that the tariffs could slow down the U.

The move is in retaliation to Trump's tariff threats on Canada, and is expected to raise energy costs for 1.5 million US homes.

During the US civil war (1861-1865) there was talk of forceable American annexation of Canada because of British support for the Confederacy, but it remained just talk. The year after that war ended, in June 1866, a group of 1500 Irish-Americans crossed the Niagara River into Canada.

Mark Carney is a newcomer to elected politics with decades of experience in finance. After his landslide victory, he pledged to continue tariffs on the U.S. "until the Americans show us respect."