BBC:
In his latest efforts to salvage a peace deal with Farc rebels, Colombian leader Juan Manuel Santos is due to meet ex-President Alvaro Uribe.
The peace agreement, aimed at ending 52 years of armed conflict, was narrowly rejected by Colombians in a popular vote on Sunday.
Mr Uribe led the campaign against the peace deal.
He says it was too lenient on the rebels and wants to renegotiate some of its more controversial points.
It is believed to be the first meeting between Mr Uribe and Mr Santos since the latter was sworn in as president six years ago.
Santos: From hawk to dove
Viewpoint: What next for Colombia?
Who are the Farc?
The one-time allies became bitter rivals after President Santos decided to negotiate with the Farc rebels.
Mr Uribe has accused the president of “selling out” the country to the left-wing guerrilla.
In limbo
Sunday’s “no” vote has thrown the peace process into disarray.
What does the ‘no’ campaign want?
A Colombian peddler holds a leaflet against the ratification of a historic peace accord between the Colombian government and the FARC guerrilla reading Image copyrightAFP
Among the “corrections” those opposed to the deal have demanded are:
That those found guilty of crimes be barred from running for public office
That Farc leaders serve time in prison for crimes committed
That the Farc use their illicit gains to pay their victims compensation
That no changes be made to the Colombian constitution
Shortly after the vote, President Santos said he “would not give up” and that he would continue working for a peace agreement that is acceptable to the Colombian people until the end of his presidency in 2018.
The Farc said that “peace is here to stay”.
On Tuesday, President Santos announced that he would extend a bilateral ceasefire between the Farc and government forces until the end of October.
This prompted Farc leader Timochenko to tweet: “@JuanManSantos announces that the ceasefire with the @FARC_EPueblo will last until 31 October, and from then onwards does the war continue?”
But Colombia’s ministry of defence released a statement on Wednesday clarifying that the ceasefire had been extended “initially” until 31 October and that it could well be extended beyond that date.
The peace agreement was reached after four years of formal talks in the Cuban capital, Havana, between government and Farc negotiators.
From early on in the negotiations, President Santos announced he would put the final agreement to the Colombian people in a “yes” or “no” vote.
Polls suggested the agreement would be approved by a comfortable margin, but the deal was rejected by 50.2% of voters.