President Donald Trump’s barrage of tariffs and threats of even more levies has quickly strained the United States’ longstanding relationship with Canada.

Canadian Prime Minister Mark Carney vows to retaliate, says his country recognized that 'America has changed' and that the two countries would 'not return to our old relationship'

US President Donald Trump's 50-percent tariffs on certain Canadian goods which took effect Saturday delivered another blow to bilateral trade, renewing focus on Ottawa's efforts…