Prime Minister Mark Carney said his team walked away from trade negotiations Friday after the American side made unacceptable requests that would have infringed on Canadian sovereignty.

Speaking with reporters Saturday morning on Parliament Hill, Mr. Carney offered several examples of U.S. demands that Canada could not accept, including the fine print related to potential agreements on steel, aluminum and autos, and language that he said would have restricted Canada’s trade negotiations with other countries.

“There were some things we wouldn’t do. We were not prepared to compromise Canada’s sovereignty or to undermine key industries,” he said. “In short, they asked too much, and they offered too little.”

The Prime Minister said Canada is preparing retaliatory measures, which would be revealed in the coming days and will take effect Sept. 8.

Mr. Carney was asked about the tone of his remarks, which suggested that Canada was at war.

“You are at war when you get attacked. We got attacked,” he said. “That’s fine. We’ve got the reserves. We’ve got resilience. We’ve got the plan. We’ve got the focus. We’ll respond – we are going to focus on what we can control. We are going to build.”