On New Year 's Day 1942 , the representatives of Allied " Big Four " , the United States , the United Kingdom , the Soviet Union and China , signed a short document which later came to be known as the Declaration by United Nations and the next day the representatives of twenty-two other nations added their signatures . A new plan for the United Nations was drafted by the State Department in April 1944 . It kept the emphasis on great power solidarity that was central to Roosevelt 's Four Policemen proposal for the United Nations . The members of the Big Four would serve as permanent members of the United Nation 's Security Council . Each of the four permanent members would be given a United Nations Security Council veto power , which would override any UN resolution that went against the interests of one of the Big Four . However , the State Department had compromised with the liberal internationalists . Membership eligibility was widened to include all nation states fighting against the Axis powers instead of a select few . The Dumbarton Oaks Conference convened in August 1944 to discuss plans for the postwar United Nations with delegations from the United States , the United Kingdom , the Soviet Union , and China . The Big Four were the only four sponsoring countries of the San Francisco Conference of 1945 and their heads of the delegations took turns as chairman of the plenary meetings . During this conference , the Big Four and their allies signed the Charter of the United Nations
San Francisco Conference
United Nations Conference on International Organization
Four Policemen