Dan Driscoll, the US Army Secretary, has resigned after months of reported tensions with Defence Secretary Pete Hegseth, the White House confirmed on Monday.
The development was first reported by the Wall Street Journal and was subsequently carried by several US media outlets, including Fox News and CNN.
A White House spokesperson praised Driscoll's service, describing him as "extremely effective" in advancing President Donald Trump's agenda and highlighting his role during what were described as significant military operations.
"The US Army is stronger than ever because of his work alongside the commander-in-chief and the secretary of defence," the spokesperson said.
Role in Ukraine discussions
Driscoll had recently been involved in negotiations and discussions related to the war in Ukraine.
Considered a close ally of Vice President JD Vance, he had served in the position for approximately 18 months.
Reports of disagreements
Speculation about Driscoll's departure had circulated for weeks.
US media reports linked the resignation to disagreements with Hegseth over leadership decisions within the armed forces, including the removal of senior military officers.
Particular attention focused on the dismissal of Gen Randy George, with whom Driscoll reportedly worked closely.
While no official explanation for the resignation has been provided, several reports have described ongoing friction between the two men.
Wider turnover at the Pentagon
Driscoll is not the first senior Pentagon official to leave in recent months.
Among other departures was Navy Secretary John Phelan, who was also reported by US media to have clashed with Hegseth.
The exits have fuelled speculation about broader tensions within the Pentagon's leadership team as the administration pursues changes in military policy and command structure.
