Canadian Prime Minister Mark Carney announced that unless a last-minute breakthrough occurs, Canada will impose retaliatory tariffs ranging from 15% to 50% on hundreds of US goods starting Tuesday, with tariffs on US steel products increasing from 25% to 50%. This move is in response to the US's earlier imposition of a 50% tariff on approximately $20 billion worth of Canadian goods, marking a further escalation in the US-Canada trade war.