Donald Trump has threatened to introduce tariffs of up to 200pc on pharmaceutical imports in a bid to force more drugmakers to bring factories to the US.

On Tuesday, the US President said “very, very high” duties could be imposed on medicines imported into the US but that he was considering giving pharmaceutical groups one year “to get their act together.”

Economists have warned that higher tariffs on drugs would also hurt American patients, and that taxpayers would end up having to pay more for US government healthcare schemes.