However, Starmer has made clear to his domestic population that the UK won't be dragged into a wider war with Iran, even as London tries to figure out what role in might play in any US-led Hormuz plan.

"Ultimately, we have to reopen the Strait of Hormuz to ensure stability in the (oil) market. That is not a simple task," Starmer told reporters.

"So we're working with all of our allies, including our European partners, to bring together a viable collective plan that can restore freedom of navigation in the region as quickly as possible and ease the economic impact," he added.

Below is a key line of Starmer's:

"While we are taking the necessary action to defend ourselves and our allies, we will not be drawn into the wider war," he said.

But it seems he's trying to have his cake and eat it too, acknowledging that Britain is on board with trying to piece together a multinational security effort - and yet Starmer has stressed it would not be a NATO-led mission.

According to more of his comments at a Downing street press conference:

The prime minister said the UK, which is considering sending ships and mine-hunting drones to the Middle East, was working with allies on a “viable plan” to reopen shipping lanes. Otherwise energy prices would remain high.

“It’s a discussion; we’re not at the point of decisions yet. It’s obviously a difficult question, that goes without saying, in relation to how you safeguard maritime traffic … But we are discussing that with the US, with Gulf partners and with Europeans,” he said.

He said that while the UK would take “necessary action” to defend itself and allies “we will not be drawn into the wider war”, as concern mounts at home over the prospect of a drawn-out conflict.

“I want to see an end to this war as quickly as possible, because the longer it goes on, the more dangerous the situation becomes, and the worse it is for the cost of living back here at home,” he said.

The British leader also rolled out the first domestic relief package tied to the US and Israeli-initiated war's economic fallout, announcing a £53 million ($70 million) support plan for vulnerable households that rely on heating oil after fuel prices surged.