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President Donald Trump said late last night that he is ending all U.S. trade negotiations with Canada over an ad aired by Ontario’s provincial government featuring the voice of former President Ronald Reagan.

In the ad, Reagan is heard speaking negatively about tariffs and their impact on Americans. The Ronald Reagan Presidential Foundation and Institute said the ad misrepresents Reagan’s 1987 remarks, which it said were edited without permission.

Trump accused Canada of trying to use the ad to influence the pending Supreme Court case that could determine the fate of many of his tariffs. Ontario Premier Doug Ford said earlier this month that the province was spending $75 million to run the ads in the U.S.