In government, the officer who serves as head of state and sometimes also as chief executive. In countries where the president is chief of state but not of government, the role is largely ceremonial, with few or no political powers. Presidents may be elected directly or indirectly, for a limited or unlimited number of terms. In the U.S., the president's chief duty is to ensure that the laws are faithfully executed, which he does through various executive agencies and with the aid of his cabinet. He also serves as commander in chief of the armed forces, nominates judges to the Supreme Court, and makes treaties with foreign governments (contingent on Senate approval). The office of president is used in governments in South and Central America, Africa, and elsewhere. In western Europe executive power is generally vested in a prime minister and his cabinet, and the president, where the office exists, has few responsibilities (though France is a significant exception).