Canadian Prime Minister Mark Carney has apologised to United States (US) President Donald Trump over an advertisement that used Ronald Reagan’s words to criticise American tariffs, prompting a new flare-up in bilateral trade tensions.

The ad, which aired during the opening games of the baseball World Series between the Toronto Blue Jays and Los Angeles Dodgers, featured clips from Reagan’s 1987 radio address warning that trade barriers: “hurt every American worker and consumer.” Trump reportedly viewed the commercial as an attack on his trade policies and swiftly suspended ongoing negotiations with Canada, announcing additional tariffs on Canadian imports in retaliation.

Carney confirmed over the weekend that he had apologised directly to Trump, describing the advert as: “not something I would have done.” He said the US president had been offended but that their relationship remained: “very good.”

Ontario Premier Doug Ford, whose government paid for the campaign, said the ad had reached over one billion viewers worldwide. He acknowledged showing the clip to Carney beforehand, adding that he went ahead despite warnings. The controversy reportedly led to a heated exchange between US envoy Pete Hoekstra and Ontario’s trade representative, David Paterson, with Ford later demanding an apology from Hoekstra.

The renewed spat comes as Trump’s administration maintains steep tariffs on Canadian steel, aluminium, and automobiles, and as the US Supreme Court prepares to hear a case on the legality of the president’s broader tariff regime.