China hits back with export controls, Canada and Mexico remain under threat. USPS closes then reopens "di minimis" small package loophole

President Donald Trump is facing pressure from U.S. hospitals and generic drugmakers to exempt medical goods from his new tariffs on Chinese imports, as they join big pharma lobbyists who have said such trade barriers will cause shortages of medicines and higher prices in the United States.

China's tariffs - due to begin next Monday - would also apply to US oil and farm machinery, but more talks are due this week.