Britain supported the use of atomic bombs by the United States against Japan in World War II about a month before the first one was dropped on Hiroshima.
The revelation was made in documents recently declassified by the U.S. National Archives and Records Administration.
According to the Japan Times, the documents give details about Britain's involvement in the United States' decision to carry out the A-bombings of Hiroshima and Nagasaki in August 1945.
The report said that the British government officially expressed its support for using the new weapon against Japan at the Combined Policy Committee meeting in Washington on July 4, 1945.
Britain referred to atomic bombs as 'Tube Alloys', a codename it used for wartime research on nuclear weapons that was also used to refer to plutonium.
During the meeting, British Field Marshal Sir Henry Wilson told the meeting chaired by U.S. Secretary of War Henry Stimson that the British government 'concurred in the use of the T.A. weapon against Japan'.