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, but it will not be attending.
As he arrived in Port-of-Spain for the summit, Mr Obama said that he wanted a “new beginning with Cuba”.
Earlier 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.
Mr Obama arrived in Trinidad for the summit in the afternoon after a visit to Mexico.
Clinton admits Cuba policy failed
It is unlikely that the US president, after just three months in office, will be announcing any major policy shifts – even on Cuba – or new detailed proposals for US-Latin American relations, says the BBC’s Latin America analyst James Painter.
The formal agenda is focused on the economic downturn which has affected the whole region and on energy and security needs.
But Cuban-American relations are expected to feature, after conciliatory signals from the leaders of the two nations.
Cuba is excluded from the summit, which includes 34 members of the Organisation of American States (OAS), though Latin American leaders have been calling for the communist country to be readmitted.
OAS Secretary-General Jose Miguel Insulza said on Friday he would ask the organisation’s members to readmit Cuba, 47 years after it was suspended.
Mr Insulza said he would put the proposal to a meeting of the OAS general assembly in Honduras at the end of May.
Venezuelan President Hugo Chavez said he would veto the final declaration from the OAS summit because of Cuba’s exclusion.