Cuba has decided not to attend an upcoming hemispheric summit following talks with Colombian President Juan Manuel Santos, averting a diplomatic showdown with US leaders who had insisted Cuba not attend, Santos told reporters. Santos flew to the Caribbean island on Wednesday to discuss the summit with Cuban President Raul Castro and Venezuelan President Hugo Chavez, who is recovering from cancer surgery. The agreement brokered by Santos, who play host the summit next month, will likely defuse threats by left-leaning states allied with Havana to boycott the summit if Cuba was not invited - preventing the spat from becoming a regional diplomatic row. \"We would like to sincerely thank President Castro for his generosity in manifesting that he does not want to create a problem for the summit or for Colombia,\" Santos said at the airport as he was preparing to leave Cuba. \"Colombia wants the situation of Cuba and its participation to be discussed in a constructive manner at the Cartagena Summit,\" he added. US leaders have said Cuba cannot attend because it is not a member of the Organization of American States, the organiser of the summit. It says Cuba does not meet an OAS charter requirement that its member countries be democracies. Ecuadorean President Rafael Correa had proposed that members of the left-leaning ALBA block of Latin American and Caribbean nations boycott the conference to protest Cuba\'s exclusion. The April 14-15 summit is important to Colombia because it hopes to use the occasion to burnish its image after years of bloody conflict with left-wing guerrillas and drug traffickers. The leaders of 34 countries in the hemisphere, including US President Barack Obama, are expected to attend. Chavez and former Cuban leader Fidel Castro spearheaded the founding of ALBA in 2004 as a counterpoint to US influence in Latin America. Along with Venezuela and Cuba, members include Ecuador, Nicaragua, Antigua and Barbuda, Bolivia, the Commonwealth of Dominica and St Vincent and the Grenadines.