PORT OF SPAIN - U.S. President Barack Obama meets his counterparts in Latin America and the Caribbean on Friday, offering practical cooperation over the ideological differences that have strained U.S. ties with the region.

But the Summit of the Americas he will attend with 33 other leaders in Trinidad and Tobago looks set to be dominated by debate over Washington's enduring ideological conflict with Cuba, the only one-party communist state in the hemisphere.

Cuba, excluded from these hemispheric summits that started in 1994, is not part of the agenda, which talks of confronting the global downturn and energy and security challenges.

But with one voice, the region's governments are calling on the U.S. president to honor his pledge for change by dropping the 47-year-old U.S. trade embargo against Cuba which has ended up isolating Washington more than its original target.

This seems further than Obama is willing to go at the moment after he relaxed some specific aspects of the embargo on Monday, opening a crack in a U.S. policy dating back to the Cold War, when Cuba was a player in the U.S.-Soviet standoff.

Obama and Secretary of State Hillary Clinton made clear on Thursday that while his administration is ready to talk to Havana about a rapprochement, it expects the Cuban side to reciprocate by freeing political prisoners and improving human rights for its citizens.

I don't expect things to change overnight ... We are not trying to be heavy handed, we want to be open to engagement, but we're going to do so in a systematic way that keeps focus on the hardships and struggles that many Cubans are suffering, Obama told reporters during a visit to Mexico.

But he hinted earlier he was willing to leave behind entrenched ideological positions of the past to seek practical solutions to the serious problems facing the Americas, in particular the global economic downturn that has hit the United States as hard as it is squeezing the rest of the region.

Years of progress in combating poverty and inequality hangs in the balance. The United States is working to advance prosperity in the hemisphere by jump-starting our own recovery, Obama wrote in an op-ed article.

NO MORE COLD WAR

To confront our economic crisis, we don't need a debate about whether to have a rigid, state-run economy or unbridled and unregulated capitalism -- we need pragmatic and responsible action that advances our common prosperity, he added.

Obama's conciliatory message of offered cooperation may not be enough to appease more virulent critics of U.S. policy, such as Venezuelan President Hugo Chavez who has condemned Cuba's exclusion from regional groups and says he will not endorse the draft declaration from the Port of Spain summit.

Chavez hosted a mini-summit of his leftist allies on Thursday including Cuban President Raul Castro, in which he declared Cuba was more democratic than the United States.

Brazilian President Luiz Inacio Lula da Silva, the pragmatic socialist who leads Latin America's economic powerhouse, has a less radical message. But he says he is also seeking a concrete change in U.S. policy toward the region, including Washington's attitude to Cuba.

There is no more Cold War, there is no more armed struggle, and there's only one group which defends the armed struggle and that's the FARC (leftist Colombian rebels), Lula said after speaking with Obama by telephone on Thursday.

He said he would convey this message at Friday's summit.

Latin American diplomats said Lula would argue that no conditions be placed on Cuba's return to hemispheric groups like the Organization of American States, because the Cuban political system was the business of its own citizens.

Cuba was suspended from the OAS in 1962 at the height of the Cold War.

The Summit of the Americas falls on the anniversary of one of the worst U.S. foreign policy fiascoes in recent history, the Bay of Pigs invasion of Cuba on April 17-19, 1961.

CIA-supported Cuban exiles were routed in a battle that consolidated communist rule 90 miles from U.S. soil.

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