Nikki Haley on Saturday (20 January) questioned whether Donald Trump was mentally capable of serving as president again after he repeatedly seemed to confuse her with former US House speaker Nancy Pelosi in a campaign speech.

Speaking on Friday, Mr Trump mistakenly asserted that Haley was in charge of Capitol security on 6 January 2021, when a mob of his supporters stormed the building.

But at a rally in Manchester, New Hampshire, 24 hours later, the former president said that he took a cognitive test and “aced it” and said he believed that his “mind is stronger now than it was 25 years ago”.