The area outside the Methodist Central Hall in Westminster has been renamed from Broad Sanctuary Green to United Nations Green to commemorate the first UN general assembly meeting held at the venue in 1946.
A special service to mark the UN's inaugural meeting on the 10th January 1946 was held online on Sunday by Revd Tony Miles, Superintendent Minister and Team Leader
Revd Miles said in a statement: "Unscathed by the war, MCHW was the ideal choice to host the UN's General Assembly. The Trustees at the time, however, had to be persuaded by Foreign Minister Ernest Bevin and others that "there could be no better place than a House of God, with the atmosphere of prayer already there". The Revd Dr. William Sangster and his congregation vacated the premises to worship at the Victoria Palace and then the London Coliseum. On 26th May 1946, Prime Minister Clement Attlee, and Dr Sangster unveiled a plaque at MCHW to mark the UN's first meeting, which was on Methodist premises."
Meanwhile the UK has helped raise more than £730 million for a fund designed to assist less developed countries access coronavirus vaccines.
The milestone coincides as the UK hosts a virtual three-day visit by UN Secretary-General Antonio Guterres, starting on Sunday, to mark the 75th anniversary of the United Nations.
The UK has been match-funding every four dollars pledged to the Covax Advance Market Commitment (AMC) with £1 of public money, up to a total of £250 million.
Other countries, including Canada, Japan and Germany, have also since signed up to the scheme, pushing it passed the £730 million mark.
The Government said that the UK had contributed £548 million overall to the AMC.
Officials said the investment would help stop the spread of the disease and prevent future waves, with the UK deploying its aid budget, scientific expertise and diplomacy to the cause.
Foreign Secretary Dominic Raab said: "It is fitting that, on the 75th anniversary of the UN, the UK has led with our allies to make one billion doses of coronavirus vaccine available to vulnerable countries.
"We'll only be safe from this virus, when we're all safe - which is why we're focused on a global solution to a global problem."
Mr Guterres said: "In the midst of a Second World War that was far from won, Winston Churchill and Franklin Roosevelt - later joined by leaders of China, France, the-then Soviet Union and other allied powers - courageously set out a vision to free the world of fear and want, through cooperation.
"This vision became the United Nations and, on this very day 75 years ago, the first meeting of the UN General Assembly was held in London.
"At this time of new global turmoil, I am honoured to virtually visit the United Kingdom to mark that occasion, renew our cause of overcoming global challenges together, and celebrate a country that was instrumental in creating the United Nations and which remains, today, a crucial member state, not least in the run-up to Cop26 in Glasgow."
The UN Secretary-General took part in the virtual commemorative event on Sunday before speaking via technology with the Prime Minister, Mr Raab and Cop26 president Alok Sharma, along with others, on Monday.
He will also hold discussions with the Archbishop of Canterbury.
The broadcast is available to watch on catch-up, 'on-demand' via mchw.live from Sunday afternoon.
Additional reporting from PA.