Donald Trump has cancelled a planned working visit to London in February, claiming that he called it off because he is not a "fan" of the new embassy building he was due to open.
The decision to move the US embassy from Grosvenor Square to Nine Elms was made in 2008 under then-president George W Bush, but Trump instead blamed Barack Obama for selling "perhaps the best located and finest embassy in London for 'peanuts,' only to build a new one in an off location for 1.2 billion dollars. Bad deal."
A US embassy spokesperson later released a statement that essentially corrected the president's tweet, although did not mention him.
Labour's London mayor Sadiq Khan said Trump had "got the message" that his actions were the "polar opposite" to the city's values of inclusion and tolerance.
But Tory foreign secretary Boris Johnson hit back, calling Khan a "puffed-up pompous popinjay" who was putting the UK-US relationship at risk. Number 10 confirmed that Johnson was speaking for the government, but "in his own inimitable way".
Trump's announcement comes just four days before the new embassy is due to open to the public on 16 January. The move was motivated in large part by security concerns, with state-of-the-art measures installed in the new compound.
With a self-sufficient water system and solar panels installed on the roof, the new building was designed to be "carbon-negative" and "demonstrate exceptional environmental leadership".
It has been described as the "antithesis" of Trump, who caused international outrage when he withdrew the US from the Paris climate change agreement last year.
According to the US embassy's website, the project is "funded entirely by the proceeds of the sale of other U.S. Government properties in London, not through appropriated funds." The existing complex in Grosvenor Square is expected to be turned into a hotel.
Just over a month ago, Trump retweeted anti-Muslim videos posted by the deputy leader of the far-right British political party Britain First, drawing criticism from prime minister Theresa May, whose spokesperson described the posts as "wrong".
In a briefing to journalists on Friday morning, a Downing Street spokesperson said "of course the president would be welcome" in the UK. The president accepted the Queen's invitation for a state visit when May visited the White House last year.
"A state visit [invitation] has been extended and accepted and we’ll confirm details in due course," he said, adding that no date was confirmed. "The opening of the US embassy is a matter for the US, but the US is one of our oldest and most valued allies and our strong and deep partnership will endure.”
The president's latest tweet sparked a flood of reaction in the UK. Khan, who has clashed with Trump in the past, said his visit "would without doubt have been met by mass peaceful protests".
Hours later, Johnson tweeted that the mayor and Labour leader Jeremy Corbyn seem "determined" to put financial ties between the UK and the US "at risk".
His tweet was posted during the briefing from the PM's spokesperson, who at the time refused to say whether Johnson spoke for the government.
“I’m not going to get into commenting on a tweet I haven’t seen yet," he said.
But a Number 10 source later told BuzzFeed News: "Boris expresses himself in his own inimitable way, but we agree that any risk to the crucial US-UK relationship is not in our country’s best interests."
Labour MP Chris Bryant, a former minister, described the president's tweet as "FAKE NEWS".
David Lammy, another Labour MP, claimed Trump dropped the visit out of fear that he would be greeted by protests, while former Labour leader Ed Miliband said that Trump had recognised that “nobody wanted [him] to come”.
Nearly 8,000 people had planned to protest against the visit planned for the end of February.
J.K. Rowling, author of the Harry Potter books, tweeted a chicken emoji in response.
Theresa May's spokesperson said that Downing Street “respect[s] the public’s right to protest peacefully.”
Outside the new embassy in Vauxhall, people took selfies next to a model of Trump installed by Madame Tussauds in the wake of the announcement.
"We woke up to the news as everyone else did in the country and thought it would be a bit of fun," a spokesperson for the attraction told Sky News.
This is a developing story. Check back for updates.