Separately, China’s Commerce Ministry and its Customs Administration said the country is imposing export controls on tungsten, tellurium, ruthenium, molybdenum and ruthenium-related items to “safeguard national security interests”.

Donald Trump and Justin Trudeau in 2019. Trudeau says Canada will reinforce its border and appoint a ‘fentanyl czar’ in efforts to stop the flow of illegal drugs to the US. Source: AAP / Frank Augstein / AP

Earlier on Tuesday, Trump suspended his threat of 25 per cent tariffs on Mexico and Canada at the last minute, agreeing to a 30-day pause in return for concessions on border and crime enforcement with the two neighbouring countries.

But there was no such reprieve for China, and a White House spokesperson said Trump would not be speaking with Chinese President Xi Jinping until later in the week.

“The trade war is in the early stages so the likelihood of further tariffs is high,” Oxford Economics said in a note as it downgraded its China economic growth forecast.

China has called fentanyl America’s problem and said it would challenge the tariffs at the World Trade Organisation and take other countermeasures, but also left the door open for talks.

Mexico agreed to reinforce its northern border with 10,000 National Guard members to stem the flow of illegal migration and drugs.

The Canadian dollar earlier soared after slumping to its lowest in more than two decades. The news also gave US stock index futures a lift after a day of losses on Wall Street, and sent oil prices lower.

Trump acknowledged over the weekend that his tariffs could cause some short-term pain for US consumers.

Other analysts said the tariffs could throw Canada and Mexico into recession and trigger “stagflation” – high inflation, stagnant growth and elevated unemployment – at home.