<P> Following the drafting of the Atlantic Charter in August 1941 by British Prime Minister Winston Churchill and U.S. President Franklin Roosevelt, Churchill visited the White House for three weeks in December 1941 . During the visit, the name "United Nations" was suggested by Roosevelt to Churchill to refer to the Allies of World War II . Roosevelt proposed it as an alternative to "Associated Powers", a term the U.S. used in the First World War (the U.S. was never formally a member of the Allies of World War I but entered the war in 1917 as a self - styled "Associated Power"). Churchill accepted the idea noting the phrase was used by Lord Byron in the poem Childe Harold's Pilgrimage, which referred to the Allies at the Battle of Waterloo in 1815 . </P> <P> The name appeared in the "Declaration by the United Nations", which was drafted by Roosevelt and Churchill with Roosevelt's aide Harry Hopkins while meeting at the White House in December 1941 . The phrase "Four Policemen" was coined to refer to the four major Allied countries, the United States, United Kingdom, Soviet Union, and the Republic of China . The term United Nations was first officially used when 26 governments signed this Declaration in January 1942 . </P> <P> The concept of the United Nations as an international organisation to replace the ineffective League of Nations was formulated and negotiated among the delegations from the U.S., the U.K., the Soviet Union and China at the Dumbarton Oaks Conference in 1944 . Winston Churchill urged Roosevelt to restore France to its status of a major Power after the liberation of Paris in August 1944 . After months of planning, the UN Conference on International Organization opened in San Francisco in April 1945 attended by 50 governments and a number of non-governmental organisations involved in drafting the United Nations Charter . The heads of the delegations of the sponsoring countries took turns as chairman of the plenary meetings beginning with Anthony Eden of Britain . The UN officially came into existence on 24 October 1945 upon ratification of the Charter by the five permanent members of the Security Council--the U.S., the U.K., France, the Soviet Union and the Republic of China--and by a majority of the other 46 signatories . </P> <P> The first meetings of the United Nations General Assembly and the Security Council took place in London beginning on 6 January 1946 . The General Assembly met in Westminster Central Hall, and the Security Council met at Church House, Westminster . </P>

When did the united kingdom join the united nations