The nations of the Pacific Alliance are promising free trade with a focus towards Asia.
Together they have a population of 209 million, and a combined economic output of $2tn a year, which is about a third of all the wealth by Latin American countries, or the same as the region's powerhouse, Brazil.
The new group plans to be less political, more clearly focused on trade.
The idea is to better integrate the economies of Colombia, Mexico, Chile, and Peru.
Al Jazeera's Alessandro Rampietti reports from Buenaventura, Colombia.