The United Nations (UN) is an Earth based international organization (founded in 1945) whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and the achieving of world peace. Many members of the United Nations have sent personnel to Atlantis. (SG1: "The Torment of Tantalus")
The UN has much influence over the Stargate Program, Atlantis expedition and Destiny expedition via it's agency International Oversight Advisory, since the UN is in the lead of any extra-terrestrial diplomacy.
- UN official website