If the U.S. follows through on President Donald Trump's threat to impose massive tariffs on Canada as early as Saturday, Ottawa could hit back with retaliatory tariffs within hours or days, according to international trade lawyers.

During his first term in office, President Donald Trump oversaw the renegotiation of a continent-wide trade deal that he hailed as "the fairest, most

The president said he planned to put tariffs on America’s neighbors on Feb. 1, as he signed an executive order mandating a sweeping review of U.S. trade policy.