The Republic of Palau (Palau) emerged from the Trust Territory of the Pacific Islands (TTPI) which the United States administered on behalf of the United Nations from 1947 to 1978. Palau was the TTPI's last district to choose its political future and become a sovereign country. Upon independence in 1994, Palau entered into a 50-year Compact of Free Association (U.S. Public Law 99-658) with the United States, similar to that of its neighbors, the Federated States of Micronesia and the Republic of Palau. Palau also joined the United Nations in 1994. Under the Compact, the United States, through the Department of the Interior, provides economic and financial assistance, defends Palau's territorial integrity, and allows uninhibited access by Palauan citizens to the United States in return for exclusive and unlimited access to Palau's land and waterways for strategic purposes. The close strategic and economic ties between the United States and Palau that go back to the end of World War II are also reflected in the fact that hundreds of Palauan citizens serve in all branches of the U.S. Armed Forces and choose to further their education in the United States. Palau also uses the U.S. dollar as its currency.