Voters in Colombia have rejected a landmark peace deal with Farc rebels in a shock referendum result, with 50.24% voting against it.
The deal was signed last week by President Juan Manuel Santos and Farc leader Timoleon Jimenez after nearly four years of negotiations.
But it needed to be ratified by Colombians in order to come into force.
Addressing the nation, President Santos said he accepted the result but would continue working to achieve peace.
He said the current ceasefire remained in place and that he had ordered negotiators to travel to Cuba to consult Farc leaders on the next move.
"I won't give up," he said. "I'll continue the search for peace until the last moment of my mandate because that's the way to leave a better country to our children."
Meanwhile the Farc leader, known as Timochenko, said the group remained committed to securing an end to the war.
He also criticised the No campaign.
"The Farc deeply regret that the destructive power of those who sow hatred and revenge have influenced the Colombian people's opinion," he told reporters.
The rebels earlier agreed to lay down their weapons after 52 years of conflict to join the political process.
But critics said the deal treated the Farc, which the US still considers a terrorist group, too leniently.
The deal would have allowed rebel leaders to avoid a prison sentence if they confessed their crimes. The rebels were also promised 10 seats in congress for the next two elections.
The agreement was rejected with 50.2% of voters against it and 49.8% in favour - a difference of less than 63,000 votes out of 13 million ballots.
The surprise result means the peace process is now shrouded by uncertainty.
Former President Alvaro Uribe, who headed the "no" campaign, said all Colombians wanted peace, but that the deal needed "corrections".
"We want to contribute to a national accord and be heard," he said.