The new, revised accord will be submitted to Congress for approval, rather than put to another referendum, they added.
Last month voters taking part in that referendum surprisingly snubbed the first accord. Critics said it went too easy on the rebels, who have been waging what is now Latin America’s last major insurgency.
“The government and Farc delegations have agreed to sign the final agreement to end the conflict and build a stable and lasting peace,” negotiators from both sides said in a statement.
The new accord was first announced on November 12. The signing will take place at 11am (1600GMT) at the Colon Theatre in Bogota. The accord will later be submitted to Congress for its approval, the two sides said.
“We are working out the procedures necessary for this,” they said.
The government holds a majority in the legislature.
President Juan Manuel Santos insists the new proposal is stronger and takes into account changes demanded by his political opponents.
However his chief rival, ex-president Alvaro Uribe, has rejected even the revised deal.
Uribe has insisted, for instance, that Farc leaders should not be allowed to run for office while still serving sentences for atrocities.
“Whether the entire (current) text is voted on, or just the issues that have been sensitive and where there has been no agreement, we ought to do it by national referendum,” Uribe said.
A two-way ceasefire between the government and the Farc has been in force since August. But the sides have warned it is fragile. “This limbo is increasing the risks,” Santos told reporters.
“It is urgent that we move to the second phase of regrouping the Farc” for their demobilisation, he said.
He spoke after an urgent meeting with top officials to tackle a recent wave of alleged political killings in southern Colombia.
Fears for the ceasefire had already risen last week when two Farc guerrillas were killed in what authorities said was a clash with the army.
Uribe has offered to meet with the Farc. But the force rejected that proposal, branding Uribe an obstacle to peace.
“Uribe misgoverned, corrupted and caused bloodshed in Colombia for eight years” when he was in office to 2010, said one of the Farc’s commanders, Pablo Catatumbo, on Twitter.
“He has never wanted peace, only the defeat of the Farc, which he couldn’t achieve.”
