FACTBOX: Five facts about U.S.-Canada-Mexico summit

(Reuters) - Here are five facts about the August 20-21 summit between U.S. President George W. Bush, Canadian Prime Minister Stephen Harper and Mexican President Felipe Calderon in Montebello, Quebec.

* Leaders of the three nations started annual meetings in 2005 under what they called the Security and Prosperity Partnership, which the governments say is aimed at cooperation but which critics say will lead to a loss of sovereignty.

* The presidents and the prime minister, and possibly the media, might have to go part way by boat on the Ottawa River to the 77-year-old Chateau Montebello hotel in order to avoid protesters on land.

* Montebello hosted the 1981 summit of the Group of Seven leading industrialized nations. It was the first G7 meeting of then-President Ronald Reagan and was hosted by Liberal Canadian Prime Minister Pierre Elliott Trudeau, with Britain's Margaret Thatcher and France's Francois Mitterrand also attending.

* Among the issues the current summit are to tackle are the safety of toys and other Chinese-made products; sustainable energy; safe borders; as well as the current market turmoil.

* Opponents of the Security and Prosperity Partnership charge variously that it could lead to a North American Union with a common currency and a superhighway extending from Canada to Mexico. The governments deny this.