TORONTO — The leader of Canada’s most populous province announced that, effective Monday, his province is charging 25% more for electricity to 1.5 million American homes and businesses in response to President Donald Trump’s trade war. Ontario provides electricity to Minnesota, New York and Michigan.

“I will not hesitate to increase this charge. If the United State escalates, I will not hesitate to shut the electricity off completely,” Ontario Premier Doug Ford said at a news conference in Toronto.

“Believe me when I say I do not want to do this. I feel terrible for the American people who didn’t start this trade war. It’s one person who is responsible, it’s President Trump.”

Ford has said Ontario’s tariff would remain in place despite the one-month reprieve from Trump, noting that a one-month pause means nothing but more uncertainty. Quebec is considering similar measures with electricity exports to the U.S.

Ford’s office said the new market rules require any generator selling electricity to the U.S. to add a 25% surcharge. Ontario’s government expects it to generate revenue of $208,000 to $277,000 a day, “which will be used to support Ontario workers, families and businesses.”

The new surcharge is in addition to the federal government’s initial $21 billion worth of retaliatory tariffs that have been applied on items like American orange juice, peanut butter, coffee, appliances, footwear, cosmetics, motorcycles, and certain pulp and paper products.

Trump launched a new trade war last week by imposing tariffs against Washington’s three biggest trading partners, drawing immediate retaliation from Mexico, Canada and China and sending financial markets into a tailspin. Trump later postponed the 25% Canada and Mexico tariffs amid widespread fear of a wider trade war.

On Sunday, Mark Carney, a former central banker, was elected the leader of Canada’s Liberal Party and will be prime minister of Canada as it faces threats to its economy and sovereignty from Trump.