The Colombian government and the Revolutionary Armed Forces of Colombia (FARC) rebel group took a final step toward peace in their decades-long conflict Thursday, signing a cease-fire agreement at a ceremony in Havana.
Colombian chief negotiator Humberto de la Calle and guerrilla leader Luciano Arango signed the agreement at a ceremony in Havana before Colombian President Juan Manuel Santos and FARC commander Rodrigo "Timochenko" Londono, with UN Secretary-General Ban Ki-Moon and a host of regional leaders from Cuba, Mexico, Venezuela, Chile and El Salvador in attendance.
Santos presented Londono with the pen - made out of a bullet - used to sign the accord, telling him, "bullets have written our past, but education will write our future."
The cease-fire was years in the making, a final step in peace negotiations launched in 2012. In the agreement, both sides agreed to ban arms in the exercise of politics - a historic step for a country embroiled in civil war since the 1960s.
Negotiators have agreed on transitional justice programmes, aid to victims of the conflict, joint action against organized crime, agricultural development programmes in rebel territories and political participation for former guerrillas.
The accord "is not a capitulation," Londono said, "but the product of a serious dialogue" between two sides who have struggled for more than 50 years.
He said the accord was "the best chance for our people to reach a lasting peace."
"May this be the last day of the war," Londono said.
World leaders welcomed the signing of the cease-fire agreement.
"Today the Colombian peace process validates the perseverance of all those around the world who work to end violent conflict not through the destruction of the adversary, but through the patient search for compromise," Ban said during the ceremony.
US Secretary of State John Kerry called the agreement "welcome news to the people of that country and to all who desire peace."
"I am pleased that, after more than four years of intensive talks, the Colombian government and the FARC have achieved breakthroughs on some of the most challenging issues before them," Kerry said. "Although hard work remains to be done, the finish line is approaching and nearer now than it has ever been."
Experts warned that the is only the beginning of a long process to stabilize the country.
"Whether the cease-fire really leads to a cessation of violence depends on whether the state security forces and the FARC individual units actually stick to it and how other armed actors in Colombia behave," said Sabine Kurtenbach from the GIGA Institute of Latin American Studies in Hamburg.
Adam Isacson of the research institute Wola warned that when FARC tried to enter politics in the 1980s with the Patriotic Union, thousands of FARC members were killed. This time around, as part of peace negotiations, Colombia has vowed to protect a disarmed FARC.
"It is crucial that the demobilized guerrillas are effectively protected," Isacson said. "In previous peace efforts many former rebels were killed. That could derail the whole process."
Eleven months ago, FARC announced a unilateral ceasefire. Although Colombia suspended its air campaign against the guerrillas, the government had until now refused to end a ground offensive.
Government and guerrillas laid out a 180-day road map at the end of which FARC is to be disarmed. The disarmament is to be verified by a working group composed of government and FARC representatives and United Nations observers.
Colombia's decades-long civil war has left more than 220,000 people dead and driven millions from their homes. Santos has said a final peace treaty could be signed next month.