The Colombian government and the Revolutionary Armed Forces of Colombia (FARC) are due to announce that they have reached a final peace agreement aimed at ending more than 50 years of conflict.
A government official told Reuters news agency on Wednesday that an announcement was "imminent" and that main issues surrounding the deal had been "finalised."
Negotiators from the government of President Juan Manuel Santos and FARC have been meeting in the Cuban capital, Havana, for the past week in what is intended as the final set of negotiations in advance of a definitive peace agreement.
Wednesday's accord would oversee the demobilisation of fighters and their reintegration into civil society and participation in politics.
Timoleon Jimenez, a FARC guerrilla leader who is known as Timochenko, said on Twitter on Tuesday: "We are at the doors of important announcements that bring us close to the final deal."
Government peace negotiators echoed the anticipation, writing on Twitter: "We are now in decisive meetings on the road to peace."
Deals have also been struck on agricultural development, joint action against organised crime and drug trafficking, and a system of transitional justice with a maximum sentence of eight years for those found guilty of crimes in the conflict.
A date for the final peace accord has not been set. Once signed, the agreement will be subject to a referendum, expected by year's end. Most opinion polls suggest Colombians will back the deal.
The Colombian conflict has drawn in several leftist rebel groups, right-wing paramilitaries and drug gangs.
It has left 260,000 people dead and 45,000 missing, while another 6.6 million have been uprooted.
Human rights groups say atrocities have been committed on all sides.
