The US has already imposed a 35% levy on all Canadian goods - though most are exempt under an existing free trade agreement. It has also slapped sector-specific levies on Canadian goods, including a 50% levy on metals and 25% on automobiles.
Trump said while travelling to Asia on Saturday that he was "increasing the Tariff on Canada by 10% over and above what they are paying now". Tariffs are paid by the companies that import foreign products, not the exporters themselves.
Three-quarters of Canadian exports are sold to the US, and Ontario is home to the bulk of Canada's automobile manufacturing.
US-Canada trade minister Dominic LeBlanc said of the tariff increase: "We stand ready to build on the progress made in constructive discussions with American counterparts over the course of recent weeks.
"We will remain focused on achieving results that benefit workers and families in both the United States and Canada, and that progress is best achieved through direct engagement with the US administration."
Trump's decision comes after Ontario Premier Doug Ford said on Friday that he would pause the anti-tariff advertising campaign "so that trade talks can resume", after discussions with Prime Minister Mark Carney.
But he said it would still appear during games for the World Series, including between the Toronto Blue Jays and the Los Angeles Dodgers.
Trump responded that the advert should have been pulled down "IMMEDIATELY". A spokesperson for Ford stood by his statement on Friday.
The advert, sponsored by the Ontario government, quotes former US President Ronald Reagan, a Republican and icon of US conservatism, saying tariffs "hurt every American".
The video takes excerpts from a 1987 national radio address that focused on foreign trade.
