Trump defended the tariffs in remarks late Tuesday and did not rule out higher tariffs in the future. On Tuesday, Trump threatened Canada with doubling the duty to 50% on its steel and aluminum exports,

Mr. Trump said the decision came in response to Ontario's move to impose a 25% surcharge on electricity exports to the U.S. Mr. Trump has already imposed a 25% tariff on nearly all imports from Canada, and declared a 25% tariff rate on all steel and aluminum imports from any foreign country.