Pope Francis urged the Colombian government and the country's leftist rebels to negotiate peace. In his speech on Sunday in Havana's Revolution Square, the pope noted that the talks to end South America's longest-running conflict were facing a "crucial moment."

The leader of the world's more than 1 billion Catholics argued that neither side had the "right" to let the rapprochement fail, the Associated Press reported.

"May the blood shed by thousands of innocent people during long decades of armed conflict" sustain efforts to find a definitive peace, he said. "Please, we do not have the right to allow ourselves yet another failure on this path of peace and reconciliation.

"Thus may the long night of pain and violence, with the support of all Colombians, become an unending day of concord, justice, fraternity and love, in respect for institutions and for national and international law, so that there may be lasting peace," the Argentine-born Catholic leader added.

Iván Márquez, the leader of the Revolutionary Armed Forces of Colombia (FARC), Colombia's largest guerrilla group, responded by saying that the Pope's words "need to find comfort in Colombians' hearts" and assured that the reconciliation process would continue, according to Cartagena's El Universal.

"We need to have faith that the path [leads] toward truth, justice and reparation and not toward repetition; let us put an end to this terrible night," Márquez said. "As the Pope says, we do not have the right to grant ourselves another failure on this path of peace and reconciliation. We need a society in peace."

Colombian President Juan Manuel Santos, for his part, also welcomed the pontiff's message and promised that his government would similarly "continue on the road of peace and reconciliation," the Guardian noted.

Santos' negotiators and the FARC have reached partial agreements on land reform, an end to drug trafficking, political participation for ex-rebels and efforts to remove land mines, Reuters detailed. Negotiations on victim reparations and demobilization, meanwhile, which are held in Havana, are ongoing, the newswire added.