The Colombian government and FARC rebels signed a revised peace agreement on Thursday aiming to end their over half-a-century-old conflict.
President Juan Manuel Santos and Revolutionary Armed Forces of Colombia (FARC) leader Rodrigo Londono signed the new deal with a pen made from a spent bullet, in a low-key ceremony in the capital Bogota.
"I invite you to leave decades of violence forever in the past, to unite for all of us, for Colombia, for this dear nation, and to work together for reconciliation around shared ideals of peace," Santos said after signing.
The new accord to end 52 years of war in Latin America's fourth-largest economy was put together in just over a month after the original pact was narrowly and unexpectedly defeated in an October 2 referendum.
The Colombian government and FARC worked together in Cuba for four years to negotiate an end to the region's longest-running conflict that has killed more than 220,000 and displaced millions in the Andean nation.
Santos, who won this year's Nobel Peace Prize for his efforts to end the conflict, said the new deal was better than the original.
"It includes the hopes and observations of the vast majority of Colombians," he said.
Opposition threatens street protests
The deal was immediately sent to Congress, where it is expected to pass after being debated next week.
Santos and his allies hold a majority in the legislature.
The government and FARC both say they are under pressure for fear that their fragile ceasefire could break down.
A recent wave of alleged assassinations in conflict zones has added to calls to seal a deal fast.
But an aftermath of discord and uncertainty appears likely as opponents promised to keep resisting the peace plan, including with street protests.
"The country has spoken. It has said, 'Yes to peace, but without impunity,'" said top opponent Alvaro Uribe, a conservative ex-president.
"What we have here remains total impunity," he told a local RCN television.
Opponents say the revisions in the peace accord are only cosmetic and will still grant impunity for war crimes committed by the FARC rebels.