Donald Trump has slammed “terrible” Prime Minister Sir Keir Starmer over the war in Iran. The US President said he was “very surprised” at Britain’s refusal to take part in the US and Israel’s offensive operations in Iran, which began on February 28.

UK Prime Minister Sir Keir Starmer has made clear that the UK wasn’t involved in the attacks, in which Iran’s former Supreme Leader Ali Khamenei was killed, along with dozens of senior figures in the country. Iran has retaliated by targeting US bases in neighbouring countries in the Gulf, sparking fears that a wider regional conflict could be unleashed.

Tehran also closed the Strait of Hormuz, a vital route for global oil trade connecting the Persian Gulf to the Gulf of Oman, sending prices soaring.

The shock has been felt worldwide and has raised the price Americans pay at the pump, just as the midterm election season begins to heat up.

In the early days of the conflict, Mr Trump had said US Navy vessels would escort oil tankers through the strait, and downplayed the threat posed by Iran.

But as oil prices soared, he and his administration have been forced to consider new options. These include the idea, broached this weekend, for other countries to support the push with their own warships.

Mr Trump says he’s asked roughly a half-dozen other countries to send warships to reopen the strait, including Britain. But so far, none has committed.

The President even indicated he would use his long-planned trip to China to pressure Beijing to help with a new coalition meant to get oil tanker traffic moving through it — a notion that his treasury secretary later downplayed.

On Monday, Sir Keir said that Britain is working with allies on a plan to reopen the shipping route, but “will not be drawn into the wider war”.

The UK is discussing with the US and allies in Europe and the Gulf the possibility of using mine-hunting drones that Britain has in the region, the PM said, but signalled that the UK is unlikely to dispatch a warship. Other countries have similarly been resistant to getting involved.

It provoked an angry reaction from Mr Trump hours later. In remarks to reporters at The White House on Monday, he fumed: “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, you know, NATO and all of these things to protect you.”

The Republican firebrand appeared to suggest that he had asked the UK to send two aircraft carriers to the region. “He didn’t really want to do it,” Mr Trump said, seemingly in reference to Sir Keir.

Mr Trump suggested Sir Keir had changed his mind and later offered to do so, but the President turned him down, as, in his estimation, the war had “essentially ended” by then.

“I think it’s terrible,” the President said, but made a renewed call for Britain to get involved. “I was not happy with the UK,” he said. “I think they’ll be involved, yeah, maybe, but they should be involved enthusiastically.”

The Express has contacted the UK Cabinet Office for comment.

The US has offered a number of explanations for the attacks on Iran, including an imminent threat to the United States and the need to destroy the country’s missile and military capabilities, though critics have called for clarity on the basis for military action.

The war stretched into its 17th day on Monday with new strikes by Israel against Iran and little sign thus far that Tehran’s authoritarian regime is looking to heed Mr Trump’s calls to surrender.

Ali Khamenei’s son, Mojtaba Khamenei, has been announced as his successor as Supreme Leader, though he hasn’t been seen since the war began. Iran confirmed that he was injured in the attacks, which killed several of his family members, but his condition is unknown.