Canadian Prime Minister Mark Carney said Ottawa will apply countertariffs on $20 billion of U.S. products on Sept. 8, escalating the feud rocking one of the world’s biggest trading relationships.

“We take this step reluctantly,” Carney said Saturday, acknowledging it will raise costs and reduce choice for Canadians, hit innocent U.S. companies, and make it harder for the two countries to work together.

Carney said he was left with little choice after trade talks with President Donald Trump’s administration broke down on Friday night, and the U.S. put import taxes of 50% on items such as plywood, liquor, electrical equipment and hockey gear from Canada.