The United States has imposed 50 per cent tariffs on 20 billion dollars’ worth of Canadian products. The tariffs came into effect early today. Canada immediately said it would retaliate following the failure of last-minute talks to ease tensions between the two historic allies. The new US tariffs will affect about five per cent of Canada’s annual exports to the United States. The products include hockey sticks and tongue depressors. Canadian Prime Minister Mark Carney said Canada would match the tariffs dollar for dollar.