The idea for the proposed United Nations began as part of the vision of U.S. President Franklin Delano Roosevelt in which the United States , the Soviet Union , the United Kingdom and China would lead the post-World War II international order . These countries , with the addition of France , would assume the permanent seats on the United Nations Security Council . At the February 1945 conference in Malta , it was proposed that the permanent members have veto power . This proposal was adopted shortly after at the Yalta conference . While at Yalta , they began sending invitations to the San Francisco conference on international organization . A total of 46 countries were invited to San Francisco , all of which had declared war on Germany and Japan , having signed the Declaration by United Nations
February 1945 conference in Malta
Malta Conference (1945)
United Nations Conference on International Organization