Petro took office in 2022 with the aim of reaching peace deals with the various dissident groups fighting for control over Colombia's lucrative cocaine trade.

But with four months left in his term, no significant progress has been made toward that goal.

Petro, himself a former guerrilla, had been engaged in peace talks since 2023 with Calarca, commander of a dissident faction of the defunct Revolutionary Armed Forces of Colombia (FARC).

Calarca's faction known as "EMBF" had refused a 2016 peace deal in which FARC agreed to lay down arms.

In another major setback, Colombia's largest armed drugs trafficking organization, the powerful Clan del Golfo, ruled out a peace deal on Tuesday with Petro -- who is set to conclude his four-year term on August 7.

Both negotiations were central pillars of Petro's "Total Peace" plan to reach deals with armed factions in the world's largest cocaine producer.

Calarca has pressed on with attacks against security forces and civilians in areas where his guerrilla group is active, mostly on the border with Venezuela and in the Amazon region.