The president’s threat comes as Canada seeks closer ties with Europe amid its deteriorating relationship with Washington.

Trump told reporters Wednesday that he might respond with “serious tariffs” if Canada were to become integrated with the 27-member EU to a degree that he perceived would be hostile to the U.S. amid a trade war with its northern neighbor.

https://www.politico.com/news/2026/09/16/trump-threatens-to-impose-serious-tariffs-on-europe-if-canada-joins-eu-as-associate-member-01081525