President Donald Trump has threatened to block the opening of a bridge connecting the US and Canada until Washington is "fully compensated for everything" it has given to its northern neighbour.

The Gordie Howe International Bridge, connecting the Canadian province of Ontario to the US state of Michigan, would not open until Ottawa "treats the United States with the Fairness and Respect that we deserve", Trump wrote on social media.

According to the project's website, the bridge is being funded by the Canadian government but will be publicly owned by both Canada and Michigan.

It is unclear how Trump could block its opening, but he said negotiations would begin immediately without elaborating.

Spanning the Detroit River, the bridge is expected to open to traffic pending formal tests and approvals in early 2026. Construction began in 2018, but the project has been a point of contention between the countries for more than a decade.

It is estimated to have cost $6.4bn CAD (£3.4bn), according to the Canadian Broadcasting Corporation.

In the statement on his Truth Social platform, Trump said that the US should own "at least one half of this asset". He also suggested that Canada owned both the Canadian and US sides of the bridge.

The organisation developing the bridge, the Windsor-Detroit Bridge Authority, is wholly owned by the Canadian government, according to the project's website.

Trump wrote: "The Canadian Government expects me, as President of the United States, to PERMIT them to just 'take advantage of America!'"

"I will not allow this bridge to open until the United States is fully compensated for everything we have given them," he added.

The Moroun family - the American owners of the neighbouring Ambassador Bridge that also connects Detroit to Canada - appealed to Trump during his first term to stop construction of the new bridge, arguing that it infringed on their exclusive ability to collect tolls.

In response, Trump and then-Prime Minister Justin Trudeau issued a joint statement saying the bridge was a "vital economic link" between the countries.

Trump on Monday pointed to recent trade disputes between the two countries, saying that "the Tariffs Canada charges us for our Dairy products have, for many years, been unacceptable".

He also said that a trade deal signed between Canada and China last month would "eat Canada alive".

Trump continued: "The first thing China will do is terminate ALL Ice Hockey being played in Canada, and permanently eliminate The Stanley Cup."

Canada's bridge authority, the Ontario premier's office and the Detroit mayor's office did not immediately respond to requests for comment.