The U.S. president on Tuesday reiterated his claims on Canada’s territory as he increased tariffs, threatening to bring the country’s economy to its knees.

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.

The sudden shifts in trade policy have forced energy regulators and grid operators in northern border states to scramble to assess potential disruptions.

Ontario Premier Doug Ford threatened to impose a 25% surcharge on or shut off the electricity the province exports to Michigan, New York and Minnesota.