Canada will respond immediately and forcefully if the United States goes ahead with a threat to impose tariffs, Prime Minister Justin Trudeau said on Friday, warning Canadians that they could be facing tough times.

Trudeau has appeared on multiple U.S. news networks to warn Canada’s neighbors that their pocketbooks are at risk of becoming collateral damage in Trump’s trade war. “Anything an American president does to hurt the Canadian economy will also hurt American consumers and American workers and American growth,” he told CNN’s Jake Tapper last week.

Trump said in an Oval Office signing ceremony on Monday that his administration will impose a 25% tax on goods from Canada and Mexico that may come as soon as February 1 – a move that could raise prices for American consumers.