President Donald Trump said in an Oval Office signing ceremony Monday evening that his administration will impose 25% tariffs on Mexico and Canada on February 1, an extraordinary change in North American trade policy that could raise prices for American consumers.

Trump underscored his intention to use tariffs as a tool of international economic policy and an increasingly vital source of government revenue.

North American car companies have operated across borders for three decades. Tariffs would raise prices and cost jobs in the short run, analysts say.