Defense Secretary Chuck Hagel officially announced on Friday that the president had nominated Robert Work as deputy secretary of Defense.
"[Work] is a highly respected and nationally recognized strategic thinker, practitioner, and expert on national security, as well as budgeting, technology, military affairs," said Hagel.
Work, 61, served as under secretary of the Navy from May 2009 to March 2013, and is a retired Marine Corps officer. He is currently the CEO of the Center of a New American Security.
"The president and I both appreciate Bob's willingness to serve his country once again and return to the Department of Defense," he said.
Hagel thanked Christine Fox, former director of the Cost Assessment and Program Evaluation office, who was filling in as acting deputy secretary.
Hagel also announced the president's appointment of Air Force Gen. Paul Selva as commander of U.S. Transportation Command.
Selva is currently the commander of Air Mobility Command.
"I have high expectations for all these leaders. [The Department of Defense] and our country will rely on them, and they'll rely on their integrity and their leadership," Hagel said.