Acting U.S. Secretary of Defense Patrick Shanahan meets with Portuguese Minister of Defense João Titternigton Gomes Cravinho at the Pentagon, Washington, D.C., June 14, 2019.

WASHINGTON — President Donald Trump announced Tuesday he will not nominate acting Defense Secretary Patrick Shanahan to hold the position in a permanent capacity. He said Army Secretary Mark Esper will become acting Defense secretary.

"Acting Secretary of Defense Patrick Shanahan, who has done a wonderful job, has decided not to go forward with his confirmation process so that he can devote more time to his family," Trump wrote in a post on Twitter.

"I thank Pat for his outstanding service and will be naming Secretary of the Army, Mark Esper, to be the new Acting Secretary of Defense. I know Mark, and have no doubt he will do a fantastic job!" he wrote in a second tweet.

Trump tweet

"It has been a deep honor and privilege to serve our country alongside the men and women of the Department of Defense," Shanahan wrote in a statement on the heels of Trump's announcement.

"After significant reflection, I have asked to be withdrawn from consideration for Secretary of Defense and will resign my position as Deputy Secretary of Defense. I will coordinate an appropriate transition plan to ensure that the men and women in harm's way receive all the support they need to continue protecting our great nation," he added.

Esper had widely been discussed as a possible replacement nominee. Trump told reporters later Tuesday that he will "most likely" nominate Esper to become Defense Secretary permanently, though he did not say when he will do so.