U.S. hits back with WTO challenge against Canada's retaliatory tariffs

OTTAWA -- The United States fired back Monday at the Canadian government's retaliatory tariffs on American imports by launching a formal challenge with the World Trade Organization. The Trump administration also called countermeasures aimed at the U.S. by Canada and other trading partners "completely without justification under international rules." The federal Liberal government introduced reciprocal duties earlier this month on some U.S. imports after the White House slapped Canada and others