Trump’s move deepens a rift between two North American countries that have suffered a debilitating blow to their decades-old alliance.

Trump this spring imposed a 25% tariff on cars and car parts, including those from Canada. But certain cars and parts qualify for preferential treatment under the USMCA, meaning the 25% tariff applies only to the non-U.S. content of the automobile or part.

Multiple states bordering Canada could feel the greatest impact of a 35 percent tariff on Canadian products starting August 1.