Cuba prepares to mark the 50th anniversary of its victory over a US-backed overthrow effort at the Bay of Pigs as it convenes a Communist Party congress that sets new political and economic goals for the island.
The anniversary celebration coincides with the first Communist Party congress since 1997, set to reaffirm the "socialist character of the revolution" while examining wide-ranging economic reforms proposed by President Raul Castro.
A military parade Saturday in Havana's Revolution Square marks what Cuban officials call the victory over "American imperialism" in April 1961, when Fidel Castro's forces turned back the invasion of CIA-backed Cuban exiles on a beach on the southern coast of Cuba.
The clash left 161 dead in Cuba along with 107 from the invaders, and Cuba took 1,189 prisoners who were exchanged in 1962 for $53 million worth of food and medicine, but the incident set US-Cuba relations on a downward spiral that led to an economic embargo by Washington.
Following the anniversary ceremonies will be a three-day congress of the ruling Communist Party. Delegates will vote on the reform program proposed by Raul Castro and formalize the retirement of his brother, revolutionary leader and longtime president Fidel Castro.
Raul Castro, 79, has said the reforms are a way to "update" the Cuban model. "Either we change course or we sink," the president said in announcing the party congress.
The president who took over from his brother in 2006 has said that Cuba, which for decades followed the Soviet model as part of the communist bloc, has to revise its system without copying others.
So far Cuba has refused to adopt major market-oriented economic reforms or a multiparty system.
But Cuba in January already began a process of axing 500,000 state employees as part of an ambitious overhaul designed to build up a private sector in an economy that has been run on communist lines since Fidel Castro took power in 1959.
The events take place with Cuba no longer part of a Soviet-led bloc, but with still-tense relations with the nearby United States.
Although US President Barack Obama has sought to ease some aspects of the embargo on the communist state, relations have seen a chill since the December 2009 arrest of a US contractor for distributing laptops and communications equipment.
The contractor, Alan Gross, recently was convicted of "acts against the independence or territorial integrity" of Cuba, and sentenced to 15 years in prison.
Meanwhile, Havana has been demanding the release of five Cubans jailed in the United States for espionage.
Former US president Jimmy Carter last month traveled to Havana and met Fidel and Raul Castro in a visit aimed at improving US-Cuban relations, but this has failed to yield any concrete results so far.
The reforms sought by Castro seek to have former state workers absorbed by the private sector, for state subsidies to be cut, for urban cooperatives to spring up, the welcoming of foreign capital, and for companies to operate autonomously.
But the Cuban leader said last month it will take "at least five years" to see through economic reforms after running into problems with its plan to lay off half a million state workers.
"Carrying out our model is not the task of just one day, not even of one year, and because of its complexity it will require at least five years to complete its implementation," he said.
"The biggest threat to the revolution resides precisely in the mistakes we could make."