U.S. President Donald Trump has revealed he is terminating all trade negotiations with Canada over an advertisement by the Ontario government that uses the late U.S. president Ronald Reagan's own words to send an anti-tariff message to American audiences.

In a late-night post to his Truth Social platform, Trump attacked the ad, which he attributed to Canada rather than Ontario, as fraudulent and fake.

"TARIFFS ARE VERY IMPORTANT TO THE NATIONAL SECURITY, AND ECONOMY, OF THE U.S.A." Trump wrote. "Based on their egregious behavior, ALL TRADE NEGOTIATIONS WITH CANADA ARE HEREBY TERMINATED."

The Ronald Reagan Presidential Foundation & Institute also criticized the ad, saying it misrepresents Reagan’s words and that Ontario did not seek permission to use or edit the remarks

Just two weeks ago, after Prime Minister Mark Carney visited the White House, Trump directed two senior members of his cabinet to get a deal with Canada on steel, aluminum, and energy.

Ottawa was informed of Trump's decision to scrap the talks shortly before he posted on social media, a senior federal government source told Radio-Canada late Thursday.

The ad that prompted Trump's sudden cancellation of the talks comes from Ontario Premier Doug Ford's government. It contains a minute-long excerpt from then-President Reagan's April 1987 radio address about free trade.

"When someone says let's impose tariffs on foreign imports, it looks like they're doing the patriotic thing by protecting American products and jobs," Reagan, a beloved figure among free-market Republicans, says in the voice-over used in the ad.

"High tariffs inevitably lead to retaliation by foreign countries and the triggering of fierce trade wars. Then the worst happens. Markets shrink and collapse, businesses and industry shut down, and millions of people lose their jobs," the ad continues.

Trump had seen the ad earlier in the week, yet did not repond so virulently.

"I even see foreign countries now that we are doing very well with [tariffs] taking ads, 'Don't go with tariffs!' "Trump told a gathering of Republicans at the White House on Tuesday.

"I saw an ad last night from Canada. If I was Canada, I'd take that same ad also," said Trump. "But I do believe that everybody's too smart for that."