The U.S. will impose an additional 10% tariff on Canada, President Trump said on Saturday, a punitive measure in response to an ad campaign that he said misrepresented comments by former President Ronald Reagan.

Prime Minister Mark Carney took a veiled shot at the Trump administration’s trade policy on Sunday, highlighting Canada’s reliability and steadiness without naming the United States or calling out the...

In a post to Truth Social Saturday afternoon, Mr. Trump described the airing of the ad during Friday night's Game 1 of the World Series as a "hostile act."