This is a temporary position with a time limit of 210 days per the [Federal Vacancies Reform Act of 1998](https://www.gsa.gov/governmentwide-initiatives/presidential-transition/legislative-overview/the-federal-vacancies-reform-act-of-1998)  "§3345. Acting officer  "(a) If an officer of an Executive agency (including the Executive Office of the President, and other than the General Accounting Office) whose appointment to office is required to be made by the President, by and with the advice and consent of the Senate, dies, resigns, or is otherwise unable to perform the functions and duties of the office-  "(1) the first assistant to the office of such officer shall perform the functions and duties of the office temporarily in an acting capacity subject to the time limitations of section 3346;  "(2) notwithstanding paragraph (1), the President (and only the President) may direct a person who serves in an office for which appointment is required to be made by the President, by and with the advice and consent of the Senate, to perform the functions and duties of the vacant office temporarily in an acting capacity subject to the time limitations of section 3346; or  "(3) notwithstanding paragraph (1), the President (and only the President) may direct an officer or employee of such Executive agency to perform the functions and duties of the vacant office temporarily in an acting capacity, subject to the time limitations of section 3346,