Canada is preparing to retaliate after the United States imposed sweeping 50% tariffs on nearly $20 billion worth of Canadian goods, escalating the trade dispute between the longtime neighbours.

Prime Minister Mark Carney announced Saturday that Canada will respond with its own “dollar-for-dollar” tariffsbeginning September 8.

The Canadian measures will target U.S. products including steel, dairy, appliances, agricultural equipment, paper and electronics.

“We pursued every opportunity to reach an agreement that protects Canadian workers and their families,” Carney said, adding that Canada was taking the retaliatory action reluctantly.

The tariffs came into effect after several days of intense negotiations between Ottawa and Washington failed to produce a last-minute agreement.

According to Carney, Canada ultimately walked away because the United States “asked too much and offered too little.”

He also accused Washington of introducing new demands late in negotiations, including proposed restrictions that could have limited Canada’s ability to negotiate trade agreements with other countries.

Carney called that condition “unacceptable.”

The latest dispute represents another major deterioration in Canada-U.S. relations under President Donald Trump, who has increasingly used tariffs as leverage in negotiations with America’s trading partners.

The Trump administration, meanwhile, has blamed Canada for the breakdown. U.S. Trade Representative Jamieson Greer said there are currently no additional negotiations planned and indicated Washington could respond again to Canada’s retaliatory measures.

For Carney, the dispute is also another reason Canada needs to become less economically dependent on the United States.

“We can’t control the storm that blows in from Washington,” he said. “We can, however, chart a new course by building Canada strong and diversifying our trading relationships abroad.”

Asked by a reporter whether Canada was now entering a trade war, Carney delivered perhaps the strongest line of the day:

“You’re at war when you get attacked. We got attacked.”