The FARC rebel group in Colombia has called for a unilateral ceasefire as peace talks with the government get underway in Cuba.
Government negotiator Humberto de la Calle earlier said the army would continue fighting the FARC until it signed a peace deal. He stressed that the rebels must agree to give up their weapons.
FARC lead negotiator Ivan Marquez said the rebels would halt all attacks from midnight on Monday until 20 January.
Some 600,000 people have died in five decades of conflict.
The BBC reports that the negotiations in Havana are expected to focus initially on the issue of land reform in Colombia, as it was a major reason for the uprising that brought about the establishment of the FARC (Revolutionary Armed Forces of Colombia) in the early 1960s.
The FARC, who once numbered 16,000 in 2001, are now thought to have some 8000 fighters.