Colombia's government has ended a ceasefire with some factions of the EMC rebels, led by commander Ivan Mordisco, who reject peace talks, the defense ministry said on Tuesday.

The Estado Mayor Central (EMC) was formed by dissident former Revolutionary Armed Forces of Colombia (FARC) fighters who themselves reject a 2016 peace deal with the state.

"(The ceasefire) will continue for three months with the Gentil Duarte block, the Jorge Suarez Briceno block, and the Raul Reyes front," the defense ministry said in a message via X.

The government in March suspended a ceasefire with the EMC in certain provinces because of ongoing violence.

The move stoked demands by a majority of units in the EMC to reinstate the ceasefire, eventually provoking an internal division that saw various fronts pull out of the talks.

The ceasefire will continue in provinces such as Norte de Santander, Antioquia, Meta and Caqueta.

Ivan Mordisco, whose legal name is Nestor Gregorio Vera, was a much-feared commander in the FARC before he began leading dissident rebels.

President Gustavo Petro has promised to end Colombia's 60-year conflict, which has killed 450,000 people, through new peace deals, but he is confronting significant hurdles, including the fraught EMC negotiations, which began in October last year.

The EMC, which has an estimated 3,800 members, has built clinics, roads and bridges in areas where it exercises control, a strategy meant to bring it closer to local people and give it a stronger position at the negotiating table.