Senior US politicians have hinted at better relations with Latin America's new wave of left-wing governments - except for Cuba.
US Vice-President Joe Biden said on Saturday that the US government has no plans to lift the nearly 50-year-old illegal blockade of the socialist island.
He and President Barack Obama "think that Cuban people should determine their own fate and they should be able to live in freedom," Mr Biden said after taking part in the Progressive Governance Summit in Chile, a gathering of centre-left leaders from Latin America and Europe.
The vice-president said a "transition" was needed in Washington's policy but that he was in Chile "to talk about the economy, not Cuba."
Meanwhile, in Colombia, former US president and Obama ally Bill Clinton told a meeting of the governors of the Inter-American Development Bank to maintain relations with the left-wing governments of Colombia's neighbours.
Without naming Bolivia, Ecuador and Venezuela, Mr Clinton said that "it shouldn't be surprising that a reaction to global inequality and America's withdrawal in the last eight years" under the Bush administration had produced governments "that are either too authoritarian or too hostile to market economics or both."
The UN general assembly has repeatedly passed resolutions condemning the blockade and calling for it to end.
Washington's isolation has increased in recent years as new progressive governments across the US's "back yard" of Latin America and the Caribbean have forged close ties with the ever-defiant Cuban people.
Despite the blockade, Cuba has provided practical solidarity across the developing world.
Mr Biden stressed that the White House was committed to the region.
"President Obama and I are absolutely committed to working closely with our neighbours in the hemisphere," he said at Chile's La Moneda presidential palace after meeting President Michelle Bachelet.
At a ceremony in Pretoria on Friday, South African President Kgalema Motlanthe bestowed the gold medal of the Order of the Companions of OR Thambo on Fidel Castro, presenting it to Cuban ambassador Angel Fernandez.
The order, named after former ANC president Oliver Thambo, is South Africa's highest award for solidarity with the anti-apartheid struggle.
It had previously been awarded posthumously to Martin Luther King Jr, Salvador Allende and Mahatma Gandhi.