The Canadian dollar hit a three-week low against the greenback on Thursday as U.S. President Donald Trump said that tariffs on Canadian goods will go into effect on March 4, clearing up some confusion on the timing and dashing hopes of a reprieve.

Canada sends about 75 per cent of its exports to the U.S., including oil, which fell to a two-month low. U.S. crude oil futures were trading 2.8 per cent lower at $68.75 a barrel.