Canada’s new retaliatory tariffs on tens of billions of dollars in American goods took effect Tuesday, imposing duties as high as 50% on hundreds of products as the increasingly bitter trade dispute between Washington and Ottawa continues to escalate.

The new levies, which took effect at 12:01 a.m. on Sept. 8, cover $27.6 billion worth of U.S. imports, according to the Canadian government. Products affected include steel and aluminum goods, dairy products, household appliances, agricultural equipment, pulp and paper products, plastics and electronics. Depending on the product, the new tariff rate is 15%, 25% or 50%.

Ottawa announced the measures in August after negotiations with the Trump administration failed to produce a new trade agreement. Canada said the tariffs were designed to match U.S. duties on Canadian products dollar for dollar.

Canadian Prime Minister Mark Carney had described the rapidly deteriorating trade relationship in unusually stark terms shortly before announcing the countermeasures.

“We were attacked. You’re at war when you get attacked. We got attacked,” Carney told reporters on August 22. “That’s fine. We’ve got the reserves. We’ve got the resilience. We’ve got the plan. We’ve got the focus. We will respond.”

Under the new Canadian tariff schedule, numerous American goods are subject to the maximum 50% rate. Among the products included in various tariff categories are dairy goods, steel and aluminum products, clothing and other consumer and industrial merchandise. The Canadian government’s official list runs to hundreds of tariff classifications.

Other American products face duties of 25%, including categories of household appliances and other manufactured goods, while certain industrial products are subject to a 15% tariff. Canada said the individual rates were set to correspond with the U.S. tariff imposed on comparable Canadian goods.

Although the duties are imposed by Canada on American imports — meaning the direct tariff is paid when those goods enter Canada — the measures could have consequences on both sides of the border. U.S. exporters may face weaker Canadian demand or pressure to lower prices, while Canadian importers and consumers could face higher costs for affected American products.

The impact could be particularly significant for American industries that rely heavily on the Canadian market. Manufacturing and automobile-producing states in the Midwest have extensive commercial ties with Canada, while dairy-producing states including Wisconsin and Vermont could be affected by the higher barriers facing U.S. dairy exports.

Even with the new tariffs, the targeted products account for only a portion of the enormous volume of commerce moving between the two countries. The United States and Canada remain deeply integrated economically, with supply chains — particularly in the automobile and aerospace industries — frequently crossing the border multiple times during production.

The latest Canadian action followed the Trump administration’s decision to impose 50% tariffs on $27.6 billion in Canadian goods beginning Aug. 22. Canada said its new measures were a direct response to those U.S. tariffs.

President Donald Trump, meanwhile, escalated the dispute further this week by threatening Canadian aircraft manufacturer Bombardier with the loss of access to the American market unless it begins manufacturing its jets in the United States.

“If they want our Market, they must build here, and stop treating America like a ‘piggybank,’” Trump wrote on Truth Social.

Trump said Bombardier would no longer be permitted to sell its aircraft in the United States unless it shifted manufacturing south of the border, though the administration did not immediately explain the legal mechanism it would use to implement such a restriction.

Bombardier pushed back by emphasizing the extent of its existing American operations. The Montreal-based company employs thousands of workers in the United States and says its supply chain includes approximately 2,800 American companies across 47 states. It also spends more than $2.5 billion annually with U.S. suppliers.

The dispute over Bombardier illustrates how intertwined the two economies remain. Many components used in Bombardier aircraft, including engines, are manufactured in the United States, while the company has facilities and service centers in several states.

Canada’s tariffs themselves were imposed after the United States targeted Canadian products including dairy goods and a range of manufactured products. Negotiations between the two governments collapsed on Aug. 21 following days of talks in Washington.

The worsening confrontation has also raised questions about the future of the United States-Mexico-Canada Agreement, the free-trade pact that replaced NAFTA and took effect in 2020. The highly integrated North American economy has operated under the agreement even as Washington and Ottawa have increasingly resorted to tariffs and other trade restrictions.

Canadian government data show that the United States remains by far Canada’s largest export market, making the economic relationship difficult for either country to unwind quickly. Carney has nevertheless said his government intends to accelerate efforts to reduce Canada’s dependence on its southern neighbor.

For businesses and consumers, the immediate impact will vary significantly depending on the product and where it is purchased. Canada’s tariffs do not mean that American shoppers will suddenly pay 50% more for Canadian products; rather, they make specified American goods more expensive to import into Canada. The economic effects could nevertheless reach U.S. producers if Canadian buyers reduce purchases or switch to suppliers elsewhere.

The latest round of tariffs adds another layer to a trade fight that has broadened well beyond conventional import duties, with the Trump administration also moving against Canadian access to U.S. government procurement and threatening restrictions on specific Canadian industries.

Trump has made clear that he wants to sharply reduce U.S. economic reliance on Canadian products.

“I don’t want Canadian cars, I don’t want Canadian parts, I don’t want Canadian anything,” Trump said on Truth Social last month. “They’ve been ripping us off for decades, and it’s going to stop.”