(Reuters) – Colombia’s President Juan Manuel Santos has said he is optimistic that Venezuela would continue to support the peace talks with Marxist FARC guerrillas should ailing President Hugo Chavez die and be succeeded by Vice President Nicolas Maduro.

Chavez, a fiery socialist leader who is fighting to recover from cancer surgery, has played a key role in pushing the talks between Colombia and the Revolutionary Armed Forces of Colombia, or FARC, as they try to end almost fifty years of war.

“I’m optimistic, if Maduro is the person that replaces Chavez, of continued Venezuelan support,” Santos said on a debate show on Caracol Radio late on Monday.

He acknowledged Maduro’s help in the initial stages of the peace talks, which have been taking place in Cuba and entered a third round on Tuesday, saying that Chavez had appointed Maduro to “push the process”.

Chavez, who missed his own inauguration last week for a new, six-year term, has not been seen in public nor heard from since his fourth surgery a month ago. The 58-year-old is suffering from an undisclosed form of cancer in his pelvic area.

The silence from the normally-vocal leader has convinced many Venezuelans that his momentous 14-year rule of the South American OPEC nation could be nearing an end.

Before leaving for Havana, Chavez urged Venezuelans to back Maduro should the cancer leave him incapacitated. Since the Jan. 11 operation he has suffered multiple complications including a severe lung infection, according to terse official bulletins.

Venezuela’s constitution says a new election must be held within 30 days if the president steps down or dies.

There is concern that Chavez’s demise could hurt chances to reach a peace agreement between Colombia and the guerrillas.

Colombia’s five-decade-old war has destabilized the border regions of neighboring Venezuela and Ecuador, making those areas transit routes for guns and drugs.

In the past, Colombian governments have accused Venezuela in particular of giving the FARC rebels refuge and support. But ties between Caracas and Bogota have improved dramatically since Santos came to power in 2010.