WASHINGTON — President Donald Trump on Monday threatened to block the opening of a new Canadian-built bridge across the Detroit River, demanding that Canada turn over at least half of the ownership of the bridge and agree to other unspecified demands in his latest salvo over cross-border trade issues.

“We will start negotiations, IMMEDIATELY. With all that we have given them, we should own, perhaps, at least one half of this asset,” Trump said in a lengthy social media post, complaining that the United States would get nothing from the bridge and that Canada did not use U.S. steel to built it.

The Gordie Howe International Bridge, named after a Canadian hockey star who played for the Detroit Red Wings for 25 seasons, had been expected to open in early 2026, according to information on the project’s website. The project was negotiated by former Michigan Gov. Rick Snyder — a Republican — and paid for by the Canadian government to help ease congestion over the existing Ambassador Bridge and Detroit-Windsor tunnel. Work has been underway since 2018.

It’s unclear how Trump would seek to block the bridge from being opened, and the White House did not immediately return a request for comment on more details. The Canadian Embassy in Washington also did not immediately return a request for comment.

Trump’s threat comes as the relationship between the U.S. and Canada increasingly sours during the U.S. president’s second term. The United States-Mexico-Canada trade agreement is up for review this year, and Trump has been taking a hard-line position ahead of those talks, including by issuing new tariff threats.

Canadian Prime Minister Mark Carney, meanwhile, has spoken out on the world stage against economic coercion by the United States.

Sen. Elissa Slotkin, D-Mich., said the Canadian-funded project is a “huge boon” to her state and its economic future. “You’ll be able to move cargo from Montreal to Miami without ever stopping at a street light,” Slotkin told The Associated Press.

“So to shoot yourself in the foot and threaten the Gordie Howe Bridge means that this guy has completely lost the plot on what’s good for us versus just what’s spite against the Canadians,” Slotkin said.

Michigan, a swing state that Trump carried in both 2016 and 2024, has so far largely avoided the brunt of his second-term crackdown, which has targeted blue states with aggressive immigration raids and cuts to federal funding for major infrastructure projects.

Trump and Democratic Gov. Gretchen Whitmer have also maintained an unusually cordial relationship, with the president publicly praising her during an Oval Office appearance last April. The two also shared a hug last year ahead of Trump’s announcement of a new fighter jet mission for an Air National Guard base in Michigan.

While Canada paid for the project, the bridge will be operated under a joint ownership agreement between Michigan and Canada, said Stacey LaRouche, press secretary to Whitmer.

“This is the busiest trade crossing in North America,” LaRouche said, saying the bridge was “good for Michigan workers and it’s good for Michigan’s auto industry” as well as being a good example of bipartisan and international cooperation.

“It’s going to open one way or another, and the governor looks forward to attending the ribbon-cutting,” LaRouche said.

Rep. Shri Thanedar, the Democratic House representative of Detroit, said blocking the bridge would be “crazy” and said Trump’s attacks on Canada weren’t good for business or jobs. “The bridge is going to help Michigan’s economy. There’s so much commerce between Michigan and Canada. They’re one of our biggest partners,” Thanedar said.

Democratic Rep. Debbie Dingell of Ann Arbor brushed aside the president’s threat, saying she’s looking forward to the bridge’s opening later in the spring. “And I’ll be there,” Dingell said.

“That bridge is the biggest crossing in this country on the northern border. It’s jobs. It’s about protecting our economy. It was built with union jobs on both sides,” said Dingell. “It’s going to open. Canada is our ally.”