The United Nations (UN) is an intergovernmental organization that aims to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmonizing the actions of nations. It is the largest, most familiar, most internationally represented and most powerful intergovernmental . in the world. The UN is headquartered on international territory in New York City, with its other main offices in Geneva, Nairobi, Vienna and The Hague.