The National Liberation Army, Colombia's second-largest leftist rebel group, must release a civilian and a soldier held hostage before the government will agree to begin a peace process, President Juan Manuel Santos said on Monday, according to Reuters. The two sides have been holding preliminary talks for more than two years while the government negotiates a peace deal in Cuba with the Revolutionary Armed Forces of Colombia, or FARC, the country's better known leftist rebel group. The talks with FARC look set to reach a final deal in the coming months. The National Liberation Army (ELN) have been holding civilian Ramon Jose Cabrales, of eastern Norte de Santander province, for five months. Government soldier Jair de Jesus Villar was captured last week in Antioquia. Colombia's government warned last week that time was running out to begin peace negotiations with the ELN.