Colombia's FARC guerrillas said Thursday they will free a general whose capture has derailed peace negotiations a day later than announced, delaying efforts to get the talks back on track.

General Ruben Alzate will be released Sunday, the leftist rebels said in a statement, ignoring President Juan Manuel Santos's previous announcement that the highly sensitive handover would take place Saturday.

The general is the highest-ranking captive taken by the Revolutionary Armed Forces of Colombia in 50 years of conflict, and his release is the key condition for the suspended peace talks to resume.

In a statement from the Cuban capital Havana, where the talks had been taking place, the FARC defiantly set their own timetable for releasing Alzate and two captives taken alongside him, Corporal Jorge Rodriguez and army adviser Gloria Urrego.

"We can guarantee that General Alzate, Corporal Rodriguez and Dr Urrego will be able to embrace their families Sunday, unlike what happens with our members who are in Colombia's prisons," said a statement on the blog of the FARC negotiating team.

"Jailed guerrillas rot in prison with war wounds sustained during their capture," FARC commander and peace negotiator Fidel Rondon told AFP.

He said five FARC members had died in prison this year.

Alzate, 55, heads a task force charged with fighting rebels and drug traffickers in the jungle-covered department of Choco.

He was captured on November 16 as he traveled with Rodriguez and Urrego to visit a civilian energy project in the remote western region.

Santos, who has made the peace process the central initiative of his presidency, suspended talks with the FARC over the incident.

Under a deal mediated by Cuba and Norway, which are shepherding the peace process, the FARC has agreed to hand the three captives over to the Red Cross, along with two soldiers captured in combat on November 9.

But Colombians have been on edge waiting for Alzate's release, the key condition to revive the talks.

- 'What about our prisoners?' -

The FARC bristled Thursday at the use of the word "kidnapping" to describe the general's capture.

It considers its captives "prisoners of war" taken in the absence of a ceasefire.

The rebels have repeatedly called for a ceasefire, but Santos has rejected the demand, saying it would strengthen their hand.

"We are freeing the general, but what about our prisoners?" asked an article on the website.

The two-year-old talks in Havana are the most promising effort yet to end the Colombian conflict, which has killed 220,000 people and caused more than five million to flee their homes since the FARC was founded in 1964.

Two previous attempts at peace negotiations -- one launched in 1990 and another in 1998 -- failed when rebel fighters kidnapped prominent political figures.

On Tuesday the FARC released the two soldiers captured in combat, 24-year-old Paulo Cesar Rivera and 23-year-old Jonathan Andres Diaz, in a promising first step toward getting the talks back on track.

But the rebels have also accused the army of stepping up activity and clashing with its fighters in Choco.

The army denies the claim.

Santos said Wednesday -- when he announced Alzate's release for Saturday -- that military operations had been halted in the region, a pre-condition for the handover.

With an estimated 8,000 fighters, the FARC is the largest rebel group active in a conflict that has at various times also drawn in right-wing paramilitaries and drug traffickers.

Santos has also announced plans to open talks with the second-largest rebel group, the National Liberation Army (ELN), which has an estimated 2,500 fighters.