President Donald Trump on Monday threatened to prevent the opening of a new U.S.–Canada bridge unless, he said, Canada compensates the United States and treats it with greater fairness and respect.

In a social media post, Trump said he would not allow the bridge to open until the U.S. is “fully compensated for everything we have given them” and until Canada shows what he described as proper respect toward the United States. He did not name the project, but his comments appeared to refer to the Gordie Howe International Bridge, a six-lane span linking Windsor, Ontario, with Detroit, Michigan.

Trump said he intends to “start negotiations, IMMEDIATELY,” suggesting he wants to revisit the terms surrounding the bridge before it becomes operational.

The $4.7 billion project has been under construction since 2018 and is expected to open later this year, though no official opening date has been announced. The bridge is being financed and managed by the Canadian government, with major construction already complete.

The president also renewed his broader criticism of Canada, which has intensified since he launched a trade dispute with the country. In his post, Trump argued that the United States should potentially own at least half of the bridge, citing what he called the enormous revenues generated by access to the U.S. market.