(NewsNation) — President-elect Donald Trump has doubled down on merging the U.S. and Canada following Canadian Prime Minister Justin Trudeau’s resignation.

On Tuesday, Trump threatened “economic force” to annex Canada, echoing his interest in buying Greenland and controlling the Panama Canal, which suggests he plans to expand U.S. power once he takes office.

“Canada and the United States: That would be really something,” Trump said at his Mar-a-Lago news conference.

This marks the most serious threat to Canadian sovereignty since the War of 1812 when the U.S. launched 10 land incursions into Canada before a peace treaty in 1815.

Efforts at annexation date back to the 19th century

The U.S. unsuccessfully invaded Canada during the War of 1812, driven by frustration over the English Royal Navy’s actions to bring American sailors into their ships. 

Fears of annexation continued through the Civil War and Manifest Destiny but failed as the two nations became close allies in the 20th Century, according to Duane Bratt of Mount Royal University, a political science professor with a focus on Canadian foreign policy.

Today, Canada and the U.S. remain strong military and economic partners. However, some question whether Trump’s rhetoric signals U.S. ambitions to control more of the Western Hemisphere, Bratt said.

“Do we want to go back to 1812, the 1860s? Maybe Trump does, but I’m not too sure Americans do, or Canadians do,” Bratt told The Hill. 

Trump calls Canada the “51st state”

Trump has repeatedly referred to Canada as the 51st state and has threatened to impose 25% tariffs on all Canadian goods. He is preoccupied with the U.S. trade deficit with Canada, erroneously calling it a subsidy.

Trump said Tuesday he would not use the military to force Canada to join the U.S. but would rely on “economic force.” If Trump applies tariffs, a trade war looms, and Canada has vowed to retaliate.

“There isn’t a snowball’s chance in hell that Canada would become part of the United States,” Trudeau posted on X. “Workers and communities in both our countries benefit from being each other’s biggest trading and security partner.”

Trump said the U.S. doesn’t need anything from Canada. About 60% of U.S. crude oil imports are from Canada, which is also the top export destination for 36 U.S. states.

82% of Canadians opposed to joining the US

NewsNation contributor Chris Hahn suggested that if Canada joined the U.S., its senators would likely be Democrats.

“Even the most conservative Canadian is more liberal than the most liberal American, at least the average American. Somebody should point that out to him and that they would expand a Democratic majority in this country,” Hahn said.

NewsNation contributor Mick Mulvaney agreed, stating, “(Canada is) not going to become the 51st state, and all of them would be Democrats … or at least most of them, when they came in.”

Meanwhile, a Leger poll, reported by the Canadian Press, found 82% of Canadians were opposed to the idea of joining the U.S. as the next state. An October Leger poll found that when asked which American candidate they’d support if they could vote in the 2024 race, roughly two-thirds of Canadians backed Vice President Harris, and just 21% supported Trump.  

The Hill and The Associated Press contributed to this report.