Canada and Mexico draw up plans to mitigate effect of duties Trump has threatened, possibly sparking a trade war

• Trump’s tariffs explained

America’s two biggest trading partners are bracing for Donald Trump to impose sweeping tariffs on their exports after the US president repeated his threat to hit Canada and Mexico with new duties.

Officials in Ottawa and Mexico City have drawn up plans to retaliate against Washington with tariffs of their own, raising the prospect of a damaging trade war. Businesses inside the US and across the world have warned of widespread disruption if the Trump administration pushes ahead.