Donald Trump on Wednesday criticized President Joe Biden for not attending the coronation of King Charles III, as the controversial former US leader toured Scotland and Ireland.
Trump, who is seeking a rematch in next year's presidential election, branded Biden's decision to skip Saturday's landmark crowning in London as "disrespectful".
Biden will represented by his wife First Lady Jill Biden, with UK and US officials noting this is in line with precedent as no president has attended a British sovereign's coronation.
The last such ceremony occurred in 1953, when Queen Elizabeth II was crowned.
"When you have somebody that's going to be sleeping instead of coming to the coronation as president of the United States, I think it's a bad thing," Trump told Britain's GB News, Reuters reported.
"It shouldn't happen. It's disrespectful," he told Nigel Farage, a populist British politician and longtime Trump ally, in an interview at one of the latter's two golf resorts in Scotland.
Trump, 76, who formally launched his campaign last November to win back the White House for Republicans, claimed Biden was hindered by his physical condition, despite the 80-year-old president visiting the UK and Ireland last month.
"I would have attended. I think it's a very important event." Trump said.
"But certainly he should be here as a representative of our country. I was surprised when I heard that he wasn't coming."
The coronation of King Charles III will be attended by around 2,000 people, including leaders, heads of state and royals from around the world.
French President Emmanuel Macron, Australian Prime Minister Anthony Albanese and President of the European Commission Ursula von der Leyen are among the politicians set to be at the Westminster Abbey service.