Sir Keir Starmer says Donald Trump is seeking to "put pressure on me in different ways" - but has insisted that he won't "buckle under pressure".
Speaking to Sky News' political editor Beth Rigby, the prime minister said he "wanted a good relationship" with the US president and still does, but vowed he is "not going to waver" on the issue of getting more involved in the Iran war.
In an exclusive interview for the Electoral Dysfunction podcast on Thursday, Sir Keir said: "That pressure isn't going to make me waver. It's not going to make me abandon my principles or values. And that's just the way I am. That is not new.
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"I'm not going to waver on this. I'm not going to back down... I'm not going to get dragged into the war... I'm not going to buckle under pressure and that's the long and the short of it."
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So, how many times has Donald Trump attacked the prime minister over his stance on the Iran war, and what has he said?
By our count, the president has launched criticisms of the PM on at least nine different days, either on social media or to journalists.
Here's a summary of Mr Trump's remarks:
20 January - 'an act of great stupidity'
Mr Trump's criticisms of the prime minister about the conflict started before the war even began on 28 February.
The president launched an unprovoked attack on the UK government's deal to hand over sovereignty of the Chagos archipelago to Mauritius, because he wanted to use the joint UK-US base on the island of Diego Garcia, to launch attacks on Iran.
Writing on Truth Social, Mr Trump warned Sir Keir was giving away the Chagos Islands "FOR NO REASON WHATSOEVER", in an "act of total weakness", and a further "act of GREAT STUPIDITY".
18 February - 'a big mistake'
The following month, having made more conciliatory noises towards Sir Keir about the deal, he stepped up his attacks again - also on Truth Social.
He called the agreement a "big mistake" and said the UK was handing over sovereignty because of "claims of entities never known before... they are fictitious in nature".
Spelling out the connection between the criticism and the upcoming conflict, Mr Trump explained: "Should Iran decide not to make a Deal, it may be necessary for the United States to use Diego Garcia, and the Airfield located in Fairford [Gloucestershire], in order to eradicate a potential attack by a highly unstable and dangerous Regime".
As it turned out, Sir Keir initially denied the US permission to launch strikes on Iran from Diego Garcia and RAF Fairford - and then the criticism really stepped up.
02 March - 'very disappointed'
Three days into the Iran war, Mr Trump began what has become a routine criticism of the PM.
He told The Telegraph he was "very disappointed in Keir" and that he "took far too long" to reverse his decision to not let the US use UK bases to bomb Iran.
03 March - 'not Winston Churchill'
The next day, he stepped this criticism up, telling The Sun that Sir Keir "has not been helpful... I never thought I'd see that from the UK."
In a news conference from the Oval Office that afternoon, the president made his first televised criticisms, saying he was "not happy with the UK" before delivering the line: "This is not Winston Churchill we're dealing with."
07 March - 'we don't need them'
A little over a week into the conflict, Mr Trump came up with a new insult, suggesting that Sir Keir offered to send both the Royal Navy's aircraft carriers to the Middle East - something the UK government has denied.
He wrote: "The United Kingdom, our once Great Ally, maybe the Greatest of them all, is finally giving serious thought to sending two aircraft carriers to the Middle East. That's OK, Prime Minister Starmer, we don't need them any longer - But we will remember. We don't need people that join Wars after we've already won!"
This insult has bcome a recurring theme in the president's attacks on the PM throughout the conflict.
16 March - 'the Rolls-Royce of allies'
Mr Trump repeated his attacks on the UK, this time saying he asked the PM to send ships and that Sir Keir said "he really didn't want to do it".
The president continued: "I said 'You don't want to do it? We've been with you. You're our oldest ally and we spend a lot of money on NATO and all of these things to protect you'. I think it's terrible. I was very surprised."
He also said he was "not happy" with the UK, a nation - he said - that was once considered "the Rolls-Royce of allies".
Separately, he repeated the ship story again, and claimed: "The prime minister... he says, well, I'd like to ask my team.
"I said, you don't have to worry about a team. You don't have a team. You're the prime minister. You can make a decision... So it's very disappointing."
17 March - 'not Winston Churchill' (x2)
The following day, the president repeated one of his favourite insults, saying "unfortunately Keir is no Winston Churchill", while hosting the Irish Taoiseach in the Oval Office on St Patrick's Day.
Mr Trump returned to the story of the PM offering to send both Royal Navy aircraft carriers - still denied by Number 10 - saying that he had rejected the offer because "we want things sent before the war, not after the war is won".
20 March - 'a very late response'
Speaking to reporters on the White House lawn, the president critcised the UK government for "a very late response" which he said had "never happened before".
Returning to the subject of the Chagos Islands, he said: "They didn't want us to use the island, the so-called island, that for some reason they gave up the rights to it. I was a little surprised by the UK to be honest with you. They should have acted a lot faster."
26 March - Royal Navy aircraft carriers 'are toys'
In his latest round of insults fired at the prime minister, Mr Trump has hit all of his previous talking points.
He said he was "very disappointed" with Sir Keir, he called the UK government's reaction to the war "shocking" because of the lengthy relationship between the two countries, and he repeated the story of the PM offering to send aircraft carriers to the US - twice.
On his second retelling, Mr Trump added: "We had the UK say that 'we'll send' - this is three weeks ago - 'we'll send our aircraft carriers', which aren't the best aircraft carriers by the way. They're toys compared to what we have."
The president repeated his claim he told the UK not to "bother" - before launching an attack on Sir Keir and the Chagos deal.
"He's a liberal, that's the way they think," the president added in reference to the agreement.
Addressing the prime minister's initial ban on the US using the base on Diego Garcia, Mr Trump added: "I said, you got to be kidding. Not good. They made a big mistake."
(c) Sky News 2026: All the times Trump has attacked Starmer over Iran war - as PM insists he's not going to back
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