Canada will impose retaliatory tariffs of up to 50% on $27.6 billion worth of U.S. goods starting Sept. 8, escalating a trade dispute that intensified after weekend negotiations broke down and new U.S. tariffs took effect. The measures will target products including steel, aluminum, furniture, clothing, paper and dairy, with rates matching U.S. duties dollar for dollar and rate for rate. The targeted goods represent about 8% of total U.S. exports to Canada in 2025, according to U.S. Census Bureau data. The announcement followed President Donald Trump's pledge to raise tariffs on Canadian cars and auto parts from 25% to 50% on Jan. 1, 2027, while also applying the higher rate to steel and trucks. In the first half of 2026, the United States exported $175.8 billion in goods to Canada, its second-largest export market after Mexico and 14% of total U.S. exports. Canadian Prime Minister Mark Carney said U.S. negotiators had asked too much and offered too little, while criticizing the use of economic integration as a weapon.