Latin American and Caribbean nations have agreed to set up a new regional body without the US and Canada.
The new bloc would be an alternative to the Organisation of American States (OAS), the main forum for regional affairs in the past 50 years.
Mexico has been hosting a regional summit in the beach resort of Cancun.
Cuban President Raul Castro was quick to applaud Mr Calderon's announcement as a historic move toward "the constitution of a purely Latin American and Caribbean regional organisation".
Venezuelan President Hugo Chavez earlier expressed his support for the proposal, citing it as a move away from US "colonising" of the region.
On Monday, Bolivian President Evo Morales proposed that it begin operating in July 2011 with a summit hosted by Venezuela.
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