Leaders from across the Americas are gathering for a summit which will see most of them meeting US President Barack Obama for the first time.
The global economic crisis and US-Cuban relations are expected to dominate the talks in Trinidad and Tobago.
Many regional leaders say Cuba should be part of the Summit of the Americas.
US Secretary of State Hillary Clinton welcomed an offer from Cuban President Raul Castro to open talks, saying the old US policy towards Cuba had failed.
Mr Castro said on Thursday that he was ready to talk about "everything" with the US, including human rights, political prisoners and freedom of the press.
His comments came after the US eased its long-standing embargo of the communist nation, allowing Cuban Americans to visit relatives in Cuba and send money home more easily.
Speaking on Friday in the Dominican Republic, Mrs Clinton acknowledged that US policy towards Cuba had failed.
"We are continuing to look for productive ways forward because we view the present policy as having failed," she said at a press conference.
"We welcome his comments and the overture they represent, and we are taking a very serious look at how to respond," Mrs Clinton said.
