The alliance was formed with the express purpose of improving regional integration and moving toward complete freedom in the movement of goods, services, capital and people between the four member states.

Together, these four countries have a combined population of more than 230 million people and make up roughly 35 percent of Latin American GDP.

At the same summit seven observers were admitted: the Dominican Republic, Ecuador, El Salvador, France, Honduras, Paraguay, Portugal, among others.

[7] The Pacific Alliance currently has 54 observer states as of 2024, including economic heavyweights such as Australia, Canada, China, France, Germany, Italy, Japan, South Korea, Spain, the United Kingdom and the United States, as well as three of the five Southern Common Market (Mercosur) countries and a member of the Bolivarian Alliance for the Peoples of Our America (ALBA).

[8] Analysts describe the Pacific Alliance as a tool to practise a kind of joint "nation-branding" to promote trade and investment and to enhance the international status and visibility of the member states.

[8] In addition to reducing trade barriers, the Pacific Alliance has begun several other projects for regional integration, including visa-free tourist travel,[9] a common stock exchange, and joint embassies in several countries.

In November 2014, Mexico opened its first trade office in Africa; located in Casablanca and shared with the other Pacific Alliance members.

Canada has also been mentioned as a candidate to join the alliance, and called a "natural fit" by Mexico's vice-minister of foreign affairs, Sergio Alcocer.

[19] However, on 8 July 2022, President Rodrigo Chaves Robles announced that Costa Rica had applied to become a full member of the Alliance.

[20] Ecuador has been critical of the alliance in conjunction with other leaders of ALBA,[21] but its president, Rafael Correa, has also speculated on a possible future bid if integration advances in areas other than trade.

[22] Guatemala has expressed concrete interest in joining the Pacific Alliance and is pursuing trade deals with current members as a precursor to a possible membership application.