In the United States, the president can use the veto power to prevent a bill passed by the Congress from becoming law. Congress can override the veto by a two-thirds vote of both chambers.
All state and territorial governors have a similar veto power, as do some mayors and county executives. In many states and territories the governor has additional veto powers, including line-item, amendatory and reduction vetoes. Veto powers also exist in some, but not all, tribal governments.