Patriotic sentiment is bursting in Canada after President Trump’s threat to apply hefty tariffs and even annex the country. The damage to the two nations’ relationship could be lasting.

Canadian Prime Minister Justin Trudeau told a business gathering on Friday that US President Donald Trump’s threat to annex Canada “is a real thing,” two Canadian business leaders who were at the meeting confirmed to CNN.

Prime Minister Justin Trudeau on Friday said President Donald Trump’s talk of making Canada the 51st U.S. state is “a real thing” and is linked to the country’s rich natural resources, local media reported.