Secretary of the Army Dan Driscoll is stepping down, the White House confirmed on Monday.

The Trump administration did not give a reason for Driscoll's departure.

The secretary spoke to President Trump and submitted his resignation, according to a source familiar with the developments.

Driscoll, who is a close ally of Vice President JD Vance, served as Army Secretary for 18 months.

White House Deputy Press Secretary Anna Kelly gave the following statement to Scripps News:

“Secretary Driscoll has been highly effective in advancing President Trump’s agenda to Make America Strong Again at the Department of the Army by providing outstanding leadership during historic military operations, restoring an emphasis on readiness and lethality, assisting with negotiations between Russia and Ukraine, and more. The United States Army is more powerful than ever thanks to his work alongside the Commander-in-Chief and Secretary of War.”

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Driscoll's departure is the latest in a high-profile exodus from top military ranks. Defense Secretary Pete Hegseth fired Army Chief of Staff Gen. Randy George in April, and dismissed other high-ranking officers.

Navy Secretary John Phelan stepped down abruptly in April.

Gen. Christopher Donahue, who led the Army's activities in Europe and Africa, stepped down in June.

This is a developing story and will be updated.