US Pentagon chief Pete Hegseth has said more senior commanders will be removed as part of sweeping reforms to military culture, fitness and leadership standards.

"We have been and will continue to be judicious but also expeditious … more leadership changes will be made," Hegseth told more than 800 generals and admirals at Marine Corps Base Quantico in Virginia.

He said the military’s culture had been shaped by leaders who embraced what he called misplaced priorities.

"It's nearly impossible to change a culture with the same people who helped create or even benefited from that culture," he said.

"An entire generation of generals and admirals were told that they must parrot the insane fallacy that 'our diversity is our strength.'"

He criticised senior leaders for focusing on diversity and climate issues rather than combat readiness.

"No more climate change worship, no more division, distraction or gender delusions, no more debris," he said, accusing politicians of forcing the military to promote leaders "based on race, gender quotas and historic so-called firsts."

Hegseth warned officers resistant to the new approach: "If the words I'm speaking today are making your heart sink, then you should … resign."

New directives

Hegseth outlined new policies aimed at reshaping the armed forces. Combat positions will return to what he called the "highest male standards," which he said reflect the life-or-death nature of the roles.

A new combat field test will be introduced for combat arms units, to be performed at any time with full equipment.

Fitness testing will change, requiring combat troops to pass gender-neutral, age-normed assessments scored above 70 percent.

"It's completely unacceptable to see fat generals and admirals in the halls of the Pentagon and leading commands," he said.

All service members will undergo physical training and height and weight checks twice annually, while grooming standards will tighten, ending the use of beards and long hair.

The Pentagon will also reassess definitions for toxic leadership, bullying and hazing to give commanders greater authority in discipline.

Oversight systems, including inspector general and equal opportunity processes, will be revised to prevent what he called "frivolous" complaints.

Mandatory training requirements will be cut back to allow "more time in the motor pool and more time on the range," Hegseth said.

While emphasising the value of female troops, he insisted combat roles must maintain strict physical standards.