Members of Colombia's military met face-to-face Friday with Marxist rebels for the first time as talks aimed at ending a half-century war enter a decisive phase.

Peace negotiations with the Revolutionary Armed Forces of Colombia taking place in Cuba's capital the past two years still face a number of obstacles.

But reflecting mounting optimism a deal is within reach, Colombian President Juan Manuel Santos decided to send some of the military's most-decorated officers to Havana to begin discussions on how to carry out any cease-fire.

Leading the delegation is Gen. Javier Flores, head of Colombia's joint chiefs of staff. He has been one of the FARC's fiercest battlefield adversaries, having led an elite, U.S.-trained unit that took out several top guerrilla leaders.