Pakistan, Aug. 22 -- The United States has imposed 50% tariffs on some Canadian goods after trade talks between both countries collapsed. Canada has pledged dollar-for-dollar retaliation.

The new duties took effect shortly after midnight and cover about $20 billion of Canadian goods. The affected products represent slightly more than 5% of Canada's US exports.

Canadian Prime Minister Mark Carney suspended trade negotiations and ordered Canada's negotiators to return home. He described the latest US proposals as unfair and economically damaging.

Meanwhile, US Trade Representative Jamieson Greer said Canada declined to finalize a proposed trade agreement. He called the decision a missed opportunity for closer economic cooperation.

The l...