The Federal Government of Mexico is the national government of the United Mexican States, the central government established by its constitution to share sovereignty over the republic with the governments of the 31 individual Mexican states and one Federal District, and to represent such governments before international bodies such as the United Nations. Similar to the federal government of the United States of America, the Mexican federal government has three branches: executive, legislative, and judicial. Through the system of separation of powers each of these branches has some authority to act on its own, some authority to regulate the other two branches, and has some of its own authority is regulated by the other branches. The seat of the federal government is in the Distrito Federal, or simply, "D.F." Mexico's government takes place in a framework of a federal presidential representative democratic republic whose government is based on a congressional system, whereby the President of Mexico is both head of state and head of government, and of a multi-party electoral system. The federal government functions per the Political Constitution of the United Mexican States, as enacted in 1917, and as amended.