Threats by President-elect Donald Trump to impose U.S. tariffs on its immediate neighbors appear to have created a split between Canada and Mexico, after Canadian officials said problems with the two countries' borders were not comparable.

The leaders of Mexico and Canada responded quickly, and in different ways. Justin Trudeau, Canada’s prime minister, jumped on the phone to Mr Trump to chat about the “intense and effective connections” between their countries. His deputy, Chrystia Freeland, released a statement about the importance of border security.