A full-blown trade war between the U.S. and Canada could lead to a recession in both countries, economist says.

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.

A government official says Canada is already examining possible retaliatory tariffs on certain items from the United States should President-elect Donald Trump follow through on his threat to impose sweeping tariffs on Canadian products.