Paraguay's President Fernando Lugo waves before the Mercosur summit in Montevideo, Uruguay,Tuesday, Dec. 20, 2011. Mercosur is a regional trade block formed by Argentina, Uruguay, Paraguay, Brazil. The block has Bolivia, Chile, Colombia, Ecuador, Peru and Venezuela as associated states. (AP Photo/Matilde Campodonico)

Paraguay's President Fernando Lugo waves before the Mercosur summit in Montevideo, Uruguay,Tuesday, Dec. 20, 2011. Mercosur is a regional trade block formed by Argentina, Uruguay, Paraguay, Brazil. The block has Bolivia, Chile, Colombia, Ecuador, Peru and Venezuela as associated states. (AP Photo/Matilde Campodonico)