The US urged the UK and the EU on Friday to reach a compromise on Northern Ireland’s post-Brexit trading arrangements after Boris Johnson threatened to tear up the agreement between the two sides.

The British prime minister said during a trade mission to India that his government was willing to take unilateral steps to reform the Brexit deal, which has bedevilled UK-EU relations since taking effect.

Asked whether he was prepared to legislate to give British ministers powers to neuter elements of the so-called Northern Ireland protocol in UK law — as first reported by the Financial Times — Johnson said: “Of course. That goes without saying.”