Trump's new threat of tariffs on Canada and Mexico will hit far beyond autos and retail, with chemicals companies and freight rails key cross-border players.

While much about the threatened tariffs is still unclear, experts predict they would be bad news for all three economies, with few winners.

As U.S. President Donald Trump mulls imposing 25% duties on imports from Canada and Mexico on Feb. 1, focus has shifted to the sectors likely to bear the brunt of the tariffs. About 28%, or about $844 billion,