Donald Trump announced on Saturday that he will raise US tariffs on Canada by 10% in retaliation for an anti-tariff advertisement sponsored by the Ontario government, which has further strained one of the world’s largest trade partnerships.

The statement, posted on Trump’s Truth Social account, came after several days of public disputes over the ad, which referenced Ronald Reagan’s support for free trade and provoked the US president’s anger.

“Because of their serious misrepresentation of the facts, and hostile act, I am increasing the Tariff on Canada by 10% over and above what they are paying now,” Trump said Saturday on social media.

He further accused the ad of being a “fraud” and said the “sole purpose” of it was “Canada’s hope that the United States Supreme Court will come to their ‘rescue’ on Tariffs that they have used for years to hurt the United States”, he added.

“Now the United States is able to defend itself against high and overbearing Canadian Tariffs (and those from the rest of the World as well!),” the president wrote.

Ontario premier Doug Ford said Friday that the province will suspend its US ad campaign on Monday, after discussions with prime minister Mark Carney, in an effort to reopen trade negotiations.

The ad, which was paid for by the government of the Canadian province of Ontario, uses excerpts of a 1987 speech where Reagan says “trade barriers hurt every American worker”.

Ronald Reagan, in a blue-and-green checked flannel shirt, reading from a piece of paper into a microphone in a wood-paneled office.

The ad aired Friday during the broadcast for Game 1 of Major League Baseball’s World Series, in which the Toronto Blue Jays faced off against the Los Angeles Dodgers.

“Their Advertisement was to be taken down, IMMEDIATELY, but they let it run last night during the World Series, knowing that it was a FRAUD,” Trump posted.

Trump had previously terminated trade talks with Canada due to the ad.

It was not immediately clear what goods would be affected by Trump’s announcement.

The majority of Canadian exports to the US are exempt from tariffs because of the United States-Mexico-Canada Agreement (USMCA) that was signed during Trump’s first term.