Canada has announced retaliatory tariffs of 15 to 50 percent on nearly 700 US products, valued at about $20 billion. Ottawa said Tuesday that the measures will take effect on September 8, following the implementation of new US tariffs on Canadian goods on Saturday.

Canadian officials said the new duties would broadly match the rates imposed by the United States. Products covered include goods from the steel, dairy and electronics sectors. Finance Minister François-Philippe Champagne said Canada faced an unprecedented challenge but would respond, adding that Canadians were united in their reaction.

The move follows the collapse of trade talks between the two countries. Prime Minister Mark Carney said he withdrew rather than accept what he called a bad trade agreement, alleging that late US demands were economically unreasonable and unfair. US President Donald Trump had warned Canada to “get in line” or face worse consequences, while also threatening additional tariffs, including on Canada’s auto industry next year. The dispute could further affect autos, steel, agricultural goods, dairy products and electronics.