Donald Trump has described NATO as a ‘one-way street’ as he stepped up pressure on allies to support US-led efforts to secure shipping routes in the Gulf.

“Now we’ll see if they help us,” the president said. “Because I’ve long said that we’ll be there for them, but they won’t be there for us. And I’m not sure that they’d be there.”

Trump also voiced frustration with the UK following a conversation with Prime Minister Sir Keir Starmer, saying Britain had been reluctant to commit forces earlier in the crisis.

“The UK might be considered the number one ally, the longest serving, et cetera, and when I asked for them to come, they didn’t want to come,” he said.

“And as soon as we basically wiped out the danger capacity from Iran, they said, ‘Oh well, we’ll send two ships’, and I said, ‘we need these ships before we win, not after we win.'”

He added: “I’ve long said that NATO is a one-way street.”