Trump said most US allies had rejected his push to escort ships through the crucial waterway, with French President Emmanuel Macron saying his country would "never" do so until the situation was calmer.

"I think NATO is making a very foolish mistake," Trump told reporters as he hosted Irish Prime Minister Micheal Martin in the Oval Office.

"I've long said that I wonder whether or not NATO would ever be there for us. So this was a great test."

But Trump insisted that Washington was ready to go it alone against Iran, saying that even NATO allies had agreed that the Islamic republic needed to be confronted over its nuclear program.

"We don't need too much help. We don't need any help," Trump said.

Minutes before the meeting, Trump made a lengthy post on his Truth Social platform saying US forces "no longer need" military help in the Iran war.

Trump said that "most" NATO allies had said they did not want to get involved, along with Japan, Australia and South Korea, describing the decades-old military alliance as a "one way street."

"Because of the fact that we have had such Military Success, we no longer 'need,' or desire, the NATO Countries' assistance -- WE NEVER DID!"

The 79-year-old Republican has long criticized NATO, and since returning to power in January 2025 he has pushed its members into increasing their defense spending.

Asked if he would reconsider the US relationship with NATO as he has suggested in the past, Trump said it was "certainly something that we should think about" but added: "I have nothing currently in mind."

- 'Big mistake' -

But he repeated his criticisms of foreign counterparts over the issue, saying British Prime Minister Keir Starmer "hasn't been supportive, and I think it's a big mistake."

Of Macron, he merely said that "he'll be out of office soon."

The US leader had suggested on Monday that both Paris and London would be ready to help, and said other countries he did not name were already on board.

But Macron insisted Tuesday that France would not participate in operations to open the strait in the current context, but once the situation becomes "calmer" it could participate in an "escort system" alongside other nations.

Britain has also waved off Washington's request for assistance.

Iran has targeted the energy facilities of its crude-producing neighbors and attacked and threatened tankers transiting the Strait of Hormuz, all but closing the vital waterway through which one fifth of global crude oil passes.

Trump meanwhile kept up his mixed messaging about the length and goals of the US-Israeli war on Iran, which has expanded dramatically across the Middle East and caused global oil prices to surge.

He said that Iran's "actual top leader was killed yesterday," in an apparent reference to Israel's claim that it had killed powerful national security chief Ali Larijani.

Iran was "just a military operation to me" and "we'll be leaving in pretty much the very near future," Trump said, but he remained vague about his political plan for the country after the war.

"We're going to try to get people that are going to run it well," he said.

US-Israeli strikes on February 28 killed ayatollah Ali Khamenei, the republic's long-serving supreme leader, and Iran has named his son Mojtaba Khamenei to replace him, despite reports he is injured.