US military chiefs have warned Pete Hegseth that extending the war with Iran is unsustainable.

In a reported classified warning to the US defence secretary, the leaders of the US army, navy and air force said that prolonging the conflict was critically weakening the United States’ ability to confront threats elsewhere, including at home.

Donald Trump has repeatedly said that all options remain open, including returning to full-scale conflict, in an effort to increase pressure on Iran.

Yet, six months into the conflict, the consensus of senior military leaders was that it had been “too much for too long”, The Washington Post reported, citing sources familiar with the recent assessment.

Negotiations with Tehran are at a stalemate, the Strait of Hormuz remains effectively closed, Americans are increasingly frustrated with the protracted conflict and defence officials are worried about depleted stockpiles.

In case Mr Trump orders more attacks, US central command has kept 50,000 troops on alert for months. Some forces are expected to stay in the Middle East well into 2027.

The generals and admirals, including those overseeing US operations in Europe, Asia and Latin America, said they disagreed with Mr Hegseth’s order to extend their forces, arguing it had weakened US capabilities elsewhere.

The US navy has been particularly overstretched in the conflict, providing dozens of warships and its carriers to the region for the war and then to enforce a blockade of Iranian ports.

Admiral Daryl Caudle, the chief of naval operations, said that barely a quarter of the navy’s destroyer fleet is ready to deploy, according to the report.

USS Abraham Lincoln

The USS Abraham Lincoln has endured the longest deployment since the Cold War – Will Tyndall/AFP

The USS Abraham Lincoln carrier group this week returned to San Diego after a 10-month deployment – the longest for a carrier in the post-Cold War era.

On Sunday Mojtaba Khamenei, Iran’s supreme leader, urged Muslim countries, particularly those in the Gulf, to unite against what he called their “real enemy” in a written statement.

Khamenei still has not been seen publicly since his father and other senior leaders were killed in the war’s opening strikes on Feb 28, when the US and Israel attacked.

He called the US and Israel enemies of all Islamic nations. “My enduring and repeating advice to rulers of Islamic nations,” he wrote, “is to know your real enemy, understand its plans and confront it.”

His call to action comes as Iran appears to be showing signs of struggle under the weight of the US blockade.

Long queues at petrol stations have been reported in recent days in several major cities including Tehran, Isfahan and Bandar Abbas, as fuel prices continue to rise.

On Monday, the Trump administration announced additional sanctions on Iran and Iran-linked entities to force Tehran to make concessions.

In public, however, Iranian officials have remained defiant. “The enemy has targeted our oil and gas resources, and our production has fallen. We are standing firm in the war, but we have to help increase the country’s resilience,” said Masoud Pezeshkian, the Iranian president, on Friday.

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