Donald Trump vowed to further escalate his trade wars on Tuesday, threatening US tariffs of up to 200% on foreign drugs and 50% on copper, amid widespread confusion around his shifting plans.

Hours after saying his latest deadline for a new wave of steep duties was “not 100% firm”, the US president declared that “no extensions will be granted” beyond 1 August.

“There has been no change to this date, and there will be no change,” Trump wrote on social media, a day after signing an executive order that changed the date from 9 July.