OTTAWA - Canada is preparing to hit the U.S. with dollar-for-dollar tariffs in response to new 50 per cent duties on $28 billion worth of Canadian products that took effect when talks between the two nations collapsed as negotiations neared the finish line.

Prime Minister Mark Carney was quiet publicly during the final days of negotiations, but now has now explained his rationale for telling the Canadian negotiating team, led by Canada-U.S. Trade Minister Dominic LeBlanc and chief negotiator Janice Charette, to leave the table.