A veto is a legal power to unilaterally stop an official action. In the most typical case, a president or monarch vetoes a bill to stop it from becoming law. In many countries, veto powers are established in the country's constitution. Veto powers are also found at other levels of government, such as in state, provincial or local government, and in international bodies.
Some vetoes can be overcome, often by a supermajority vote: in the United States, a two-thirds vote of the House and Senate can override a presidential veto. Some vetoes, however, are absolute and cannot be overridden. For example, in the United Nations Security Council, the five permanent members (China, France, Russia, the United Kingdom, and the United States) have an absolute veto over any Security Council resolution.