Washington, Feb. 3 -- US President Donald Trump's tariff hikes on Canada, Mexico and China went into effect Saturday evening with an announcement from the White House marking the start of a trade war that is expected to spread to other countries.

The Trump administration has levied an additional tariff of 25 per cent on imports from Canada and Mexico and 10 per cent on those from China. Oil imports from Canada will, however, be subject to a lower levy of 10 per cent.

The inflow of "Illegal aliens and drugs, including deadly fentanyl, constitutes a national emergency", the White House said in a factsheet detailing and explaining the tariff hikes. "President Trump is taking bold action to hold Mexico, Canada, and China accountable to thei...