The United Nations is an intergovernmental organization established 24 October 1945, to promote international co-operation. A replacement for the ineffective League of Nations, the organization was created following the Second World War to prevent another such conflict. At its founding, the UN had 51 member states; there are now 193. The headquarters of the United Nations is situated in Manhattan, New York City, and enjoys extraterritoriality. Further main offices are situated in Geneva, Nairobi and Vienna. The organization is financed by assessed and voluntary contributions from its member states. Its objectives include maintaining international peace and security, promoting human rights, fostering social and economic development, protecting the environment, and providing humanitarian aid in cases of famine, natural disaster, and armed conflict. During the Second World War, US President Franklin D. Roosevelt initiated talks on a successor agency to the League of Nations, and the United Nations Charter was drafted at a conference in April–June 1945; this charter took effect 24 October 1945, and the UN began operation.