US media said Hegseth directed senior Defense Department leaders to plan for cuts that could slash the defense budget by eight percent annually, or some $290 billion within the next five years.

The Pentagon did not directly deny those reports, but instead described an effort aimed at removing funding from programs favored by former president Joe Biden and using it on those advocated by his successor Donald Trump.

"Secretary Hegseth has directed a review to identify offsets from the Biden administration's FY26 budget that could be realigned from low-impact and low-priority Biden-legacy programs to align with President Trump's America First priorities for our national defense," Robert Salesses, performing the duties of deputy secretary of defense, said in a statement.

"The department will develop a list of potential offsets that could be used to fund these priorities, as well as to refocus the department on its core mission of deterring and winning wars. The offsets are targeted at eight percent of the Biden Administration's FY26 budget, totaling around $50 billion, which will then be spent on programs aligned with President Trump's priorities," the statement said.

A report from the Washington Post meanwhile described a memo from Hegseth -- dated Tuesday -- that ordered the development of plans for eight percent to be cut from the defense budget in each of the next five years.

- 'Revive the warrior ethos' -

Hegseth's memo said the proposed cuts must be drawn up by February 24, and include 17 categories that Trump wants exempted, including operations at the US border with Mexico and modernization of nuclear weapons and missile defense, the newspaper reported.

It also called for funding for Indo-Pacific Command and Space Command, but did not do so for others such as European Command, which has led the way on US strategy throughout the war in Ukraine, the Post reported.

The Defense Department "must act urgently to revive the warrior ethos, rebuild our military, and reestablish deterrence," Hegseth wrote in the memo, according to the Post.

"Our budget will resource the fighting force we need, cease unnecessary defense spending, reject excessive bureaucracy, and drive actionable reform including progress on the audit," he reportedly continued.

The Pentagon's budget for 2025 is some $850 billion and the cuts described in the memo, if implemented in full, would reduce that figure by tens of billions each year to some $560 billion by the end of the five years.

Trump has vowed to slash government spending, and Elon Musk's Department of Government Efficiency (DOGE) -- which is tasked with carrying out that effort -- reportedly visited the Pentagon last week.

Hegseth signaled support for DOGE's work at the Pentagon in a Tuesday post on X: "Let's get to work. DOGE the waste; Double-Down on warriors," he wrote.