WASHINGTON: US Defence Secretary Pete Hegseth is revoking the security clearance and personal security detail for retired Army General and former chairman of the Joint Chiefs of Staff Mark Milley, a Pentagon spokesperson said in a statement on Tuesday.

Hegseth has also directed the Department of Defence Office of Inspector General to open an inquiry into Milley’s conduct to determine whether it is appropriate to reopen an assessment of Milley’s military grade, according to the Pentagon.

“Undermining the chain of command is corrosive to our national security,” Joe Kasper, the Defence Department Chief of Staff, said in a statement.

Representatives for Milley could not be immediately reached.

The news was first reported by Fox News on Tuesday. Milley was among the preemptive pardons that former President Joe Biden issued on Jan. 20, his last day in office.

Hegseth sworn in as US defense secretary

Milley has said he was grateful for the pardon by Biden, who said Milley and others “do not deserve to be the targets of unjustified and politically motivated prosecutions.”

President Donald Trump had once suggested Milley should be executed for holding back-channel talks with China.

Milley’s photo was removed from the Pentagon shortly after Trump was sworn into office.

The second and last portrait of Milley will also be removed from the Pentagon, Fox News reported.