President Donald Trump said the sweeping tariffs that he has imposed on Mexico, Canada and China may cause "short term" pain for Americans as global markets reflected concerns the levies could undermine growth and reignite inflation.

But Mr Trump’s most incendiary claims are reserved for China. The Communist Party, he says, “has subsidised and otherwise incentivised” Chinese firms to “export fentanyl and related precursor chemicals that are used to produce synthetic opioids sold illicitly in the United States”.