Dan Driscoll had repeatedly sparred with Hegseth over Army oustings

Army Secretary Dan Driscoll submitted his resignation to President Donald Trump, three sources familiar with the matter told CNN.

Dan Driscoll had been rumored to step down at some point between now and the end of the year but the White House announced his departure Monday.

The development follows Driscoll publicly breaking with Hegseth's move to force Gen. Randy George, the ousted Army chief of staff, to retire.

Dan Driscoll leaves after 18-months in the job with White House bogged down in Iran conflict