US President Donald Trump criticized outgoing British Prime Minister Keir Starmer after the Labour leader announced he would resign, saying he had “really hurt himself” over energy, immigration and his handling of relations with Washington.

“I think he’s a lovely man,” Trump told reporters at an Oval Office event, before accusing Starmer of mishandling Britain’s energy policy by failing to exploit North Sea oil and allowing “windmills all over the place”.

“The UK buys much of its energy. You know where? Norway. You know where they get their oil? The North Sea,” Trump said. “The UK has a much better portion of the North Sea – they don’t want to do it for environmental purposes.”

Trump, who had predicted Starmer’s departure in a Truth Social post, said the British leader was “sort of a friend of mine” but had not been supportive enough of the United States on NATO and the Iran war.

The leaders had clashed over the use of British military bases in Cyprus to conduct strikes in Iran, with the US leader voicing disappointment that Britain took too long to approve the US request to use RAF Akrotiri in Cyprus to bomb Iranian targets.

“He said we can’t use the island to land. That was a first,” Trump said, adding that Starmer had eventually relented but that “was a bad move” that “hurt him badly”.

“I wish him well,” Trump said. “But he’s got two problems: energy and immigration – and crime. But energy and immigration. He’s really hurt himself very, very badly.”

Likewise, Trump said he could refuse to help NATO countries as pay back for the lack of support from member nations with the US military operation in Iran.

“We spent all of this money. And then when we want to maybe have help on small stuff… They say no we would rather not help,” he said. “Stupid thing to say, because we can say that to them if we want, and we might,” he added.

Despite strained relations with the alliance, Trump is set to attend the NATO summit in Ankara, Turkey next month. (AFP)