President Donald Trump on Wednesday threatened to impose tariffs on the European Union or halt trade with the bloc entirely if it proceeds with its plan to make Canada its first-ever "associate member."

"I think it's laughable ... Canada has been a terrible trade partner," Trump told reporters after landing in North Carolina. He conditioned his threat on the intention of European leaders, saying that "if I think it's at all a hostile act, I will put very serious tariffs or stop trading with Europe on many things."