Mexico's President Enrique Pena Nieto (R) and Chile's President Sebastian Pinera pose for photos prior to a meeting during the 13th Pacific Alliance Summit in Puerto Vallarta, Mexico, on July 24, 2018. Latin America's two key trade blocs Pacific Alliance and Southern Common Market (Mercosur) Tuesday signed a joint declaration at a summit in Mexico to promote free trade and social inclusion. (Xinhua/Francisco Canedo)