Cuba's government called a news conference Tuesday in which it is anticipated that Colombia's main leftist rebel group could announce the start of talks to end a half-century-old conflict that has claimed tens of thousands of lives, if not more.

Colombian President Juan Manuel Santos announced last week that preliminary talks to end the confrontation with the Revolutionary Armed Forces of Colombia, or FARC, already have been held. At least some of the formal discussions are expected to take place in Cuba, whose communist government has mediated in past peace efforts and maintains surprisingly good relations with Colombia's conservative government.

Cuban authorities announced the press conference in an email to the foreign press, but gave no details on who will speak for the FARC. It is believed to be the first news conference the rebels have given outside Colombia in more than a decade.

The FARC has about 9,000 fighters but has suffered major setbacks in recent years, and the smaller National Liberation Army has 3,000 combatants. Santos has said they, too, could be interested in laying down their arms, though officials have not said they are part of the current discussions.

The last peace effort with the FARC ended in disaster in 2002, after three years of talks in a Switzerland-sized safe haven carved out of southern Colombia by then-President Andres Pastrana. The rebels never agreed to a cease-fire, nor did they stop kidnappings for ransom or trafficking in cocaine.

Since then, the FARC has been stung by a U.S.-backed military buildup called Plan Colombia, and by an aggressive counterinsurgency program which roughly halved the group's numbers. Since 2008, three senior FARC leaders have been slain in military raids, including top commander Alfonso Cano.

Cuban leader Raul Castro and his brother are among the only leaders left in Latin America old enough to remember the start of the Colombian insurgency as grownups, and they have long sought to play a leading role in regional affairs.

FARC and ELN members have long lived and received medical treatment on the island, often with the tacit approval of the Colombian government. Nonetheless, their presence has been one factor in the U.S. decision to label Cuba as a state-sponsor of terrorism, a designation that Cuba hotly contests.