President Trump said in a social media post he will be increasing tariffs on Canadian steel and aluminum to 50%, starting tomorrow, in response to Ontario’s 25% surcharge on electricity coming into the United States.

“Based on Ontario, Canada, placing a 25% Tariff on ‘Electricity’ coming into the United States, I have instructed my Secretary of Commerce to add an ADDITIONAL 25% Tariff, to 50%, on all STEEL and ALUMINUM COMING INTO THE UNITED STATES FROM CANADA, ONE OF THE HIGHEST TARIFFING NATIONS ANYWHERE IN THE WORLD,” Trump wrote. “This will go into effect TOMORROW MORNING, March 12th.”

Trump also said he would declare a national emergency on electricity within the area affected by Canadian electricity shipments and threatened to raise tariffs on Canadian car imports in order to “permanently shut down the automobile manufacturing business in Canada.”

Additionally, the president insisted Canada reduce its tariffs on US dairy products following his threat last week of new reciprocal tariffs on Canadian lumber and dairy products.