"I have asked that the foreign ministry put the breaks on these discussions and put the breaks on our role as guarantor in this peace process as long as the ELN doesn't commit to stopping terrorist attacks," President Lenin Moreno told Colombia's RCN television.

Contacted by AFP, Moreno's office did not respond to requests to further clarify his remarks, and there was no immediate comment from either the government in Bogota or the ELN, the National Liberation Army.

Colombia's President Juan Manuel Santos is trying to conclude a peace agreement with the country's last active rebel group, similar to the one signed with FARC guerrillas in November 2016. The FARC has since become a political party.

His remarks came as Ecuadoran and Colombian troops pressed a hunt along their respective sides of the border for the Oliver Sinisterra Front, another rebel group responsible for the kidnapping and murder of a three-man Ecuadoran journalist team.

The massive manhunt began on Friday after the journalists' deaths were confirmed. Colombia's police chief Jorge Nieto said on Wednesday they had captured one of the group's leaders.

He identified him as Vicente Canticus Pascal, who goes by the name "Brayan".

"He is a leader of this organization which is run by Guacho," a former middle-ranking FARC commander, Nieto told reporters in the port city of Tumaco, where the Colombian hunt is focused.

He said Brayan was suspected of "direct responsibility" for attacks on police and electricity pylons in the Tumaco area that have left hundreds of thousands of people without power.

Officials believe Guacho and his group of around 70-80 rebels work for Mexico's Sinaloa cartel.

Until now, Ecuador has been unable to locate the remains of the murdered journalist team after Guacho suspended moves to coordinate the return of their remains on Monday.

The rebels have since announced the capture of another Ecuadoran couple whose whereabouts remain unknown.