Colombia’s left-wing Farc rebels have rejected criticism that efforts to end almost fifty years of conflict are moving too slowly.
Farc lead negotiator Ivan Marquez said achieving lasting peace in Colombia would take “more time”.
He spoke as the rebels and the Colombian government marked six months since peace talks began.
President Juan Manuel Santos has said he hopes a deal can be reached within months rather than years.
Peace negotiations began in Cuba in November.
Mr Marquez told reporters in the capital, Havana, on Sunday that he did not understand why the pace of talks was being described as slow.
“You have been watching the Giro d’Italia (cycle race). Some people want us to go at this pace, but if we go at this pace, we will fail.”
“We have to approach these issues with serenity, with depth if we really want to form the solid basis to build a stable and long-lasting peace,” he said.
Talks remain stalled over the issue of land redistribution in Colombia, the first of a five-point agenda.
The Colombian government has promised to return millions of hectares of stolen land to displaced peasants, one of the rebels’ main demands.
But Bogota insists that the rebels must first put down their guns and cease hostilities.
‘Intensification of violence’
Jorge Restrepo, director of Colombia’s Conflict Analysis Resource Centre, a private and independent research group, told Efe news agency that “no big changes have happened” in Colombia since the talks began.
“We have seen an intensification of violence that violates the human rights of indigenous and Afro-Colombian communities and human rights defenders.”
Mr Restrepo argued that the Farc could be trying to gain time “to retrain… and to gather strength”.
Colombia’s internal conflict began in the 1960s.
It has already claimed the lives of tens of thousands people and left millions more displaced from their land.