U.S. President Donald Trump announced a fresh 10% tariff on all Canadian imports Saturday, intensifying trade tensions with Canada over an Ontario-sponsored advertisement featuring former President Ronald Reagan that Trump labeled a “fraud.”

The new levy, added to existing duties, targets Canada’s $800 billion annual exports to the U.S.—which account for 75% of its total trade—amid stalled negotiations where Canada remains the only G7 nation without a renewed trade agreement. Trump made the announcement aboard Air Force One en route to the ASEAN summit in Malaysia, citing the ad’s continued airing during the World Series between the Toronto Blue Jays and Los Angeles Dodgers as a provocation. “It should have been pulled down IMMEDIATELY,” he posted on Truth Social.

Ontario Premier Doug Ford, who backed the minute-long ad quoting Reagan’s 1987 radio address—“Tariffs hurt every American”—had pledged Friday to pause the campaign during negotiations. However, the ad continued through the weekend, prompting Trump’s response. The Ronald Reagan Foundation criticized the spot for “selective” editing, while Ford defended it as a stand against U.S. protectionism.

The ad has aired in Republican districts to rally opposition to Trump’s tariffs, which already include a 35% blanket duty on Canadian goods (largely waived under the USMCA), 50% on metals, and 25% on autos. Ontario, Canada’s automotive hub, faces significant economic fallout.

Canadian Prime Minister Mark Carney, speaking on the sidelines of the ASEAN summit, responded with restraint: “We are ready to continue to build on the progress we had been making.” He also unveiled plans for an “ambitious budget” focused on generational investments and trade diversification, including new ASEAN partnerships.

Trade Minister Dominic LeBlanc called for “direct engagement,” while the Canadian Chamber of Commerce warned that tariffs function as “a tax on America first, then North American competitiveness.”

The dispute adds to Trump’s broader tariff campaign, which has yielded deals with the UK, Mexico, and others but remains unresolved with Canada. In a lighter moment, Ford and California Governor Gavin Newsom exchanged World Series wagers—maple syrup versus California wine—highlighting the personal diplomacy amid policy friction.

Economists warn that further escalation could shave 0.5% off GDP for both countries, threatening the stability of a $1 trillion bilateral trade relationship.