President Donald Trump on Monday agreed to a 30-day pause on his tariff threats against Mexico and Canada as America's two largest trading partners took steps to appease his concerns about border security and drug trafficking.

Last-minute phone calls pull the North American neighbours back from the brink of a trade war, but the US is still targeting Chinese imports.

The United States should pause tariffs on Canada as it did on Mexico, the head of the largest North American aerospace union told Reuters on Monday, as industry executives weighed the impact of fresh duties on plane parts and jets.