Cuban President Raul Castro flew to Caracas on Friday to attend a meeting with other allies of Venezuelan leader Hugo Chavez, who was at the airport for the arrival.
Neither man spoke to reporters, and it was unclear what they planned to discuss.
Castro is joining other national leaders of the Bolivarian Alliance, or ALBA, at the Sunday summit, including the presidents of Nicaragua and Bolivia.
Haitian President Michel Martelly also arrived ahead of Sunday’s meeting, at which he will have observer status. He said he hopes to discuss the status of Haitian migrants in ALBA countries and will seek aid for Haiti’s school food program.