The head of government is the Governor of Puerto Rico, who is elected every four years in a general election. The position is similar in nature, responsibility, and power as those of a governor of a U.S. state. The position of Governor has the overall responsibility of the state of the commonwealth, equivalent to the state of the union in the U.S. The official residence of the governor is La Fortaleza, the oldest executive mansion in continuous use in the Western Hemisphere.