Why a bridge over the Detroit River is the latest flare-up in the US-Canada trade spat

• President Donald Trump's latest spat with Canada is over the Gordie Howe International Bridge.
• He said he would not allow the bridge to open until Canada treated the United States with respect.
• Prime Minister Mark Carney said he had a "positive conversation" with Trump on Tuesday.

President Donald Trump is singing "No Canada" as a sprawling bridge connecting Ontario to Detroit nears completion.

The Gordie Howe International Bridge is set to connect Detroit and Windsor, Ontario. Construction began in 2018, with an anticipated opening planned for 2024. Delays pushed the opening to 2026 — and Trump's threats could delay it even longer.

The US and Canada are engaged in an ongoing trade spat that includes liquor sales, travel, and electric vehicles. On Monday, Trump wrote on Truth Social that he wouldn't allow the bridge to open until Canada compensated the United States "for everything we have given them."

Negotiations would start immediately, Trump wrote. The bridge now remains in a state of limbo. Here's what you need to know.

What is the Gordie Howe International Bridge?

There's already one bridge connecting Detroit and Windsor, Ontario.

The Ambassador Bridge opened in 1929. It's been privately owned by the Moroun family for decades. It reportedly carries about $360 million a day, or about 25% of the value of goods traveling between the US and Canada. It's also limited in its scale, with only four lanes, limited shoulders, and constricted traffic patterns leading up to it in Windsor.

In 2012, both Canada and Michigan approved the construction of a second bridge, the Gordie Howe. They officially broke ground in October 2018 on the 1.5-mile, six-lane bridge, which will also include a walking and biking path.

The bridge cost an estimated CA$6.4 billion, or about $4.7 billion. Canada paid for the entire project and plans to recoup its investment through toll revenues.

Michigan will also own a part of the bridge, and the Windsor-Detroit Bridge Authority will manage operations.

It was set to open this year.

Why is Trump threatening to shut down its opening?

In his Truth Social post, Trump wrote that the bridge would not open until Canada treated the US with the "Fairness and Respect that we deserve."

The feud between Trump and Canadian Prime Minister Mark Carney has reached a fever pitch. At Davos, the two world leaders exchanged fiery speeches. Canada recently reached a "preliminary agreement" for a trade deal with China, and Trump responded with the threat of 100% tariffs.

Canada's deal with China would allow up to 49,000 Chinese electric vehicles to enter the Canadian market at the "most-favoured-nation tariff rate of 6.1%." In exchange, Carney expected China to lower tariffs on Canadian agricultural tariffs.

Canada's deal with China was a point of contention in Trump's post about the bridge. He wrote that China would "eat Canada alive," and said the country would ban hockey and eliminate the Stanley Cup.

Trump wrote that the US "should own, perhaps, at least one half of this asset." (Michigan and Canada already jointly own the bridge.)

There's also the Moroun family, which owns the existing Ambassador Bridge. They've publicly lobbied Trump to stop the new bridge, going so far as to air a commercial in 2018. And on Tuesday, The New York Times reported that Matthew Moroun met with Howard Lutnick, the US Commerce Secretary, about the project. Hours after that reported meeting, Trump posted about the bridge on Truth Social.

It wasn't always like this. During Trump's first presidency, he issued a statement with then-Prime Minister Justin Trudeau in support of the project.

"We look forward to the expeditious completion of the Gordie Howe International Bridge, which will serve as a vital economic link between our two countries," the two leaders wrote.

How did Michigan and Canada react?

The negotiations have begun.

Carney said he spoke to Trump on Tuesday morning about the bridge, explaining that Canadians had paid in full for the project and that Michigan already had an ownership stake.

One of Trump's critiques was that the bridge was not built using American products. Carney said he told Trump the bridge was built with American and Canadian workers and steel from both the US and Canada.

"It was a positive conversation," Carney said.

Michigan, the second party in the agreement with Canada, doesn't seem thrilled, either. Gov. Gretchen Whitmer said that she was in communication with Trump's staff, and that the bridge was a "really important part of our economy."

And they may not wait for Trump's approval. Whitmer's press secretary said on Tuesday that the bridge would open "one way or another."