The imbalance in President Trump’s treatment of America’s closest trading partners may come from his desire to make Canada the 51st state, some Canadians believe.

Trump has justified tariffs on goods from Canada, the top U.S. export market, by accusing it of failing to stop the cross-border flow of fentanyl, even though U.S. government data shows Canada accounts for only 1% of the fentanyl that enters the United States.

Canada's main stock index slipped on Friday as investors assessed U.S. President Donald Trump's new tariff regime that included levies on Canada and dozens of other countries. The S&P/TSX composite index was down 1.