U.S. President Donald Trump on Tuesday vowed to hit the European Union with tariffs and said his administration was discussing a 10% punitive duty on Chinese imports because fentanyl is being sent from China to the U.

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.