France, Sept. 16 -- EU chief Ursula von der Leyen raised the prospect a day before Canadian leader Mark Carney was due to address the European Parliament.

Her pitch comes as both Canada and the European Union seek to pivot away from an aggressive United States under Trump's leadership.

"I think it's laughable," Trump told reporters when asked about the plan.

"If they do 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."

He added: "If it's a good intention, that's fine. If it's a bad intention, we'll put very heavy tariffs on Europe, which is a possibility."

Von der Leyen pitched closer cooperation on tech, defense and energy to Carney, who became the first non-Eur...