Beginning Monday, new market rules require any generator selling electricity to the U.S. to add a 25% surcharge, according to Ford's office. Ontario's government expects to generate revenue of $300,000 to $400,000 Canadian dollars per day, "which will be used to support Ontario workers, families and businesses."

Trade relations between the United States and Canada are worsening, and Minnesota is now one of three states caught in the middle.

Premier Doug Ford warned that he was prepared to cut off power exports to the three states entirely as long as President Trump’s tariff threats remain.