Trump’s move to impose new tariffs has bewildered the United States’ closest allies and trading partners, who have vowed to respond with levies of their own.

Mr. Trump will put a 25 percent tariff on goods from Mexico and Canada, along with a 10 percent tariff on Chinese products, Karoline Leavitt, the White House press secretary, said in a news briefing Friday.

Canada’s prime minister and Mexico’s president have ordered retaliatory tariffs against Americans, following through with their threats after U.S. Donald Trump sparked a trade war by imposing sweeping tariffs on imports from Canada,