Colombian President Gustavo Petro (L) and ELN Guerrilla First Commander Antonio Garcia (R) shake hands next to Cuban President Miguel Diaz-Canel (center) in Havana, on June 9, 2023.
Bogota, Colombia CNN  — 

The Colombian government and the National Liberation Army (ELN) – one of the oldest and largest guerrilla groups still operating in the country – have agreed to implement a bilateral, six-month ceasefire starting on August 3.

The agreement comes after months of private negotiations in Cuba, Mexico, and Venezuela, and was ratified on Friday during a ceremony in Havana presided over by Colombian President Gustavo Petro, his Cuban counterpart Miguel Diaz-Canel and the ELN’s chief commander, known by his nom de guerre ‘Antonio García.’

Both sides also pledged to hold further negotiations in Venezuela starting in August. Cuba, Mexico, Norway, and Venezuela have acted as “guarantors” for the peace talks, as well as the United Nations and the Colombian Catholic church.

The third round of peace negotiations between the Colombia's and the ELN  in Havana on May 2, 2023.

The Colombian government and the ELN have been engaged in peace negotiations since at least 2012, but the six-month ceasefire agreed on Friday is the longest agreed upon since the guerrilla group formed in 1963, said the ELN’s chief negotiator known by his alias ‘Pablo Beltrán.’

In January 2019, then-Colombian President Ivan Duque suspended peace talks after the ELN killed 22 police cadets in an attack against the national police academy in Bogota, Colombia.

Friday’s agreement is different from the historic 2016 peace agreement between the Colombian government and the Revolutionary Armed Forces of Colombia – FARC, another guerilla group operating in the country since the 1960s and was dismantled in 2017.

The ELN is still present in large swathes of the Colombian countryside and operates a military force of several thousand men according to military analysts and the Colombian military forces.

Considered a terrorist organization by the United States and the European Union, the group is accused of being involved in the production and trafficking of cocaine to finance its operation.

The agreement comes as the Petro administration wrestles with a series of scandals. Last week, Petro’s chief of staff Laura Sarabia and the Colombian ambassador to Venezuela, Armando Benedetti, both resigned amid mutual accusations of wiretapping.