According to U.S. law, there are four Assistant Secretaries of the Air Force appointed from civilian life by the President of the United States upon the advice and consent of the United States Senate. They assist the United States Secretary of the Air Force and the United States Under Secretary of the Air Force. One of the four assistant secretaries is the Assistant Secretary of the Air Force (Financial Management & Comptroller), who is responsible for "the exercise of the comptroller functions of the Department of the Air Force, including financial management functions." The duties expressly given to the Assistant Secretary of the Air Force (Financial Management & Comptroller) include determining the Department of the Air Force's budget estimates (in conjunction with the Under Secretary o