Cuba says it is "unacceptable" that it won't be invited to an upcoming regional summit, amid US objections.
The communist island has accused Washington of acting with "disdain and arrogance" over its exclusion from the Sixth Summit of the Americas.
At a news conference in Havana, Cuba's Foreign Minister Bruno Rodriguez Parrila went further.
"It is part of the economic, political and media blockade which is genocide, illegal and violates the human rights of Cubans," he said.
The US says Cuba is not sufficiently democratic to take part in the gathering in Colombia next month.
The event's host, Colombian President Juan Manuel Santos told his Cuban counterpart Raul Castro that without a consensus there could be no invitation. Santos made the trip to Havana after some nations threatened to boycott the meeting unless Cuba was put on the guest list.