The Permanent Joint Board on Defense (spelled Defence in Canadian English) was established by Canada and the United States on August 17, 1940 by joint announcement of President Franklin D. Roosevelt and Prime Minister William Lyon Mackenzie King at Ogdensburg, New York as the senior advisory body on continental military defence of North America. The board consists of both Canadian and American military and civilian representatives. The main purpose of the group is to provide policy-level consultation on bilateral defence matters. Periodically the board conducts studies and reports to the governments of the United States and Canada. The board, which is co-chaired by a Canadian and an American, meets semi-annually, alternating between either country.