"Three amigos" NAFTA summit planned: Canada PM Thu Jan 27, 1:27 PM ET Canada - AFP OTTAWA, Jan 27 (AFP) - Canadian Prime Minister Paul Martin said that US President George W. Bush (news - web sites) and Mexico's President Vicente Fox (news - web sites) had agreed to join him in a summit to tinker with the North American Free Trade Agreement. Martin has pressed Bush especially to act to strengthen NAFTA's dispute settlement mechanism, irked by the US response to rulings on issues such as Canada's softwood lumber exports to the United States. "There are gaps in NAFTA...