Trump also says he is using tariffs to "combat the scourge of fentanyl", a powerful drug that causes tens of thousands of overdose deaths in the US each year. His administration says chemicals used to make the drug come from China, while Mexican gangs supply it illegally and have fentanyl labs in Canada.

Senior aide Peter Navarro is a driver of the idea inside the White House. He pushed for reciprocal tariffs during Trump’s first term.

President Donald Trump’s desire to get even on countries by matching tariffs they have on American goods could come at a steep cost.