Colombia's government says it will sign a new peace accord with Farc rebels on Thursday, after a previous deal was rejected in a referendum last month, BBC.
The new revised agreement will be submitted to Congress for approval, rather than put to a popular vote.
But opposition groups say it still does not go far enough in punishing rebels for human rights abuses.
The deal is aimed at ending more than 50 years of armed conflict, which has killed more than 260,000 people.
In a televised address to the nation on Tuesday, President Juan Manuel Santos said: "We have the unique opportunity to close this painful chapter in our history that has bereaved and afflicted millions of Colombians for half a century."
The original deal was signed two months ago in an emotional ceremony before world leaders but it was rejected in a referendum on 2 October.
Government opponents led by former President Alvaro Uribe said the deal was too favourable to the rebels.
Farc and government negotiators worked round the clock to make more than 50 changes to make it more acceptable to conservative Colombians who despise the Farc.
Mr Uribe and other sceptics continued to claim the changes made were cosmetic.