Truman, who had succeeded Roosevelt on the latter's death on 12 April 1945, Clement Attlee, who had replaced Churchill as prime minister in July 1945, Anderson and United States Secretary of State James F. Byrnes conferred while on a boat cruise on the Potomac River, and agreed to revise the Quebec Agreement,[125] with a view to replacing it with a looser form of co-operation on nuclear matters between the three governments.[126] Groves, Secretary of War Robert P. Patterson and Patterson's advisor George L. Harrison met with a British delegation consisting of Anderson, Wilson, Malcolm MacDonald, the High Commissioner to Canada, Roger Makins from the British Embassy in Washington, and Denis Rickett, Anderson's assistant, on 15 November 1945 to draw up a communiqué. They agreed to retain the Combined Policy Committee.