On 25 March, the United Nations moved to its new headquarters in New York - not yet in Manhattan, but in the Lehman College campus in the Bronx.

Lehman College is the Bronx campus of the City University of New York. The first General Assembly meetings were held there and the Security Council meetings took place at the university sports complex.

The first session of the UN General Assembly opened on 10 January 1946 in Methodist Central Hall in Westminster, London, just across the road from Westminster Abbey and a stone’s throw from the Houses of Parliament. The UN had not yet decided where its headquarters should be by that time. The idea of siting the UN in New York was supported, in particular, by Joseph Stalin, who feared that if the new organization were remain in Europe, it could suffer the same fate as the League of Nations.

The UN had to move twice more. On 16 August 1946, the UN headquarters was temporarily located in the village of Lake Success on Long Island, in a factory which closed after the war. On 14 December 1946, the General Assembly accepted the proposed allocation of $8.5 million made by John D Rockefeller Jr to buy an area for the permanent UN headquarters. France, Great Britain and the Netherlands voted against the construction of the headquarters. Canada offered to host UN headquarters on Navy Island in Lake Ontario, near Niagara Falls. However, the choice of Manhattan was approved by a majority vote.

Architects, designers and engineers from all over the world were invited to create the UN building complex. Nikolay Basov (USSR), Oscar Niemeyer (Brazil), Ernest Cormier (Canada), Wallace Kirkman Harrison (USA), Sven Markelius (Sweden), G. A. Soilleux (Australia), Liang Sicheng (China) were among those specialists. Charles Le Corbusier (France) was the chief architect. The building was officially opened on 10 January 1951.