Donald Trump has said Britain and other countries which did not take part in the US-Israeli attacks in the Middle East should secure the Strait of Hormuz themselves.
The US President said nations that “refused to get involved in the decapitation of Iran” should “build up some delayed courage, go to the strait and just take it”.
It comes as Iran's selective blockade of the vital oil and gas shipping route, and its attacks on the Gulf states, has pushed up global energy prices, threatening to plunge the UK economy into crisis.
In the latest sign that his Middle East campaign has severely damaged long-standing relationships, Mr Trump suggested his country’s allies will “have to start learning how to fight for yourself” and buy oil from the US.
Britain was the only country named in a post by Mr Trump on his Truth Social platform on Tuesday.
He wrote: “All of those countries that can’t get jet fuel because of the Strait of Hormuz, like the United Kingdom, which refused to get involved in the decapitation of Iran, I have a suggestion for you: Number 1, buy from the U.S., we have plenty, and Number 2, build up some delayed courage, go to the Strait, and just TAKE IT.
“You’ll have to start learning how to fight for yourself, the U.S.A. won’t be there to help you anymore, just like you weren’t there for us.
“Iran has been, essentially, decimated. The hard part is done. Go get your own oil!”
The Prime Minister will chair a Cobra crisis committee on Tuesday afternoon amid warnings that household energy bills could soar by almost £300 this summer.
Sir Keir Starmer said ministers will look at "making sure that everything that we need to have in place" to respond to the looming economic crisis sparked by the Iran war is set up.
Average energy bills are forecast to rise by £288 from July as soaring wholesale costs caused by conflict in the Middle East are set to push up Ofgem's price cap.
Cornwall Insight said its prediction for the watchdog's price cap from July to September now stands at £1,929 for a typical dual fuel household - an increase of £288 or 18 per cent on April's cap.
Motorists are already counting the cost of the war, with drivers paying £544 million extra for fuel since the US-Israeli bombing campaign began.
