Via press release from the Pentagon:
Under the direction of President Trump, the Department of Defense remains focused on safeguarding our nation. We have deep respect for Secretary Mattis’ lifetime of service, and it has been a privilege to serve as his deputy secretary.
As acting secretary of defense, I now look forward to working with President Trump to carry out his vision alongside strong leaders including the service secretaries, the Joint Chiefs of Staff, the combatant commanders, and senior personnel in the Office of the Secretary of Defense.
The Department of Defense continues to be one of our nation’s bedrock institutions. Our foundational strength lies in the remarkable men and women who volunteer to serve our country and protect our freedoms, while making immense personal sacrifice. It is an honor to work with such a dedicated team committed to the greatness of our nation.