Colombia's president says he will not lower his guard against the country's main rebel group, but he believes a peace deal is possible if there is "goodwill" on both sides.
"If there is goodwill from both parts, we will reach an agreement much sooner than people expect," Juan Manuel Santos told Al Jazeera on Saturday, as peace talks between the government and the Revolutionary Armed Forces of Colombia (FARC), aimed at ending half a century of war between the two sides, is set to kick off next month.
"I think the fundamental issues that are on the table, that we agreed to discuss and agree on in order to finalise the conflict, are not that difficult," the president said in his first extensive interview with an international network.
Santos said he remained sceptical about FARC's motives, and that the Colombian military and police had been instructed to intensify their offensive against the rebels as they entered the "last track of this conflict" and could not afford to lower their guard.
He said a fundamental issue in the negotiations would be about balancing peace with justice, by finding ways to reintegrate FARC members into society while also seeing to it that those who committed crimes be punished accordingly.
He also guaranteed the safety of rebels who stop fighting. In the past, rebels who had laid down their arms were killed by government-backed death squads.
"This will not happen from the state," Santos said. "I will protect the process from everything I have in my hands. And when I say sit down and I give you guarantees, I will comply."
On Friday, FARC said it would still engage in peace talks with Colombia's government in the Norwegian capital next month, despite Santos rejecting a ceasefire proposal from the group a day before.
In an interview with The Associated Press, Marco Leon Calarca, a FARC spokesman, said the discussions could continue without a truce.
"No, we are not saying that if there is no ceasefire then we will not begin ... We are simply calling for sanity by saying that if we are going to talk, let us try and avoid more damage. If we are willing for peace, let's not hurt each other anymore. Let's not hurt our people anymore," Calarca said.
FARC leaders had said on Thursday that a key item on their agenda is to propose a truce in the decades-long conflict that has killed tens of thousands of people.
But just hours later, Santos said that would not happen.
"There's not going to be any ceasefire. We will not give anything until we get the final agreement, and I want to make that very clear," he said.
On Friday, Calarca invited the National Liberation Army, another rebel group, to also consider holding talks with the Colombian government in hopes of achieving peace.
FARC said that the talks are scheduled to begin on October 8 in Oslo, and will be the first attempt in a decade to reach a negotiated end to an armed conflict that began in 1964.
The rebel army draws its roots from anger among landless peasants in a country with a huge divide between rich and poor.
The last peace talks, in 2002, fell apart when the government concluded that the guerrillas were regrouping in a vast demilitarised zone it created and where the talks were held.
The rebels never agreed to a ceasefire, nor did they stop kidnappings for ransom or trafficking in cocaine.
Since then, the FARC has been stung by a US-backed military build up called Plan Colombia, and an aggressive counter-insurgency programme which roughly halved the group's numbers.
Since 2008, three senior FARC leaders have been killed in military raids, including top commander Alfonso Cano.