Havana (AFP) - Colombia's FARC rebels have promised to end recruitment of child soldiers, in a fresh bid to seal a peace deal ending a half-century conflict.
At talks in Cuba, the leftist guerrilla group had already pledged to stop recruiting fighters under 17, but the Colombian government said that did not go far enough.
International authorities and rights groups define any member of a force under the age of 18 as a child soldier.
"In order to advance as quickly as possible to ending the armed conflict, today we communicate to the country our decision to end the recruitment of those aged under 18 to the FARC," said a negotiator for the Marxist rebel force, Victoria Sandino.
The United Nations Resident Coordinator in Colombia, Fabrizio Hochschild, welcomed the news.
"This takes us one step closer to the end of the conflict," he told reporters. "We hope the discussions in Havana continue so that underaged girls and boys and teens, are out of the FARC's ranks as soon as possible."
The two sides have vowed to sign a peace deal by March 23 to end five decades of conflict that have left 220,000 people dead.
Wednesday's announcement aimed to ease negotiations by the FARC, whose leaders have warned in recent weeks of lingering obstacles to a peace deal.
The two sides have signed deals on four of the six agenda items at the talks: justice for victims, land reform, a political role for ex-rebels and fighting the drug trafficking that fuels the conflict.
The unsettled issues are disarmament and the mechanism by which the final accord will be ratified.
At the request of the two sides, the United Nations has agreed to send a political mission of unarmed observers to monitor disarmament and the transition to peace.
Disagreement remains over whether the peace deal should be put to a popular vote in Colombia or passed by a constituent assembly as the FARC demands.
The FARC demanded on Wednesday that Santos respond to its gesture on child soldiers by ending obligatory military service.
The state Colombian Family Welfare Institute says that between 1999 and 2015 it took in just over 5,700 minors who had been recruited by armed groups in the country.
The FARC is currently estimated to have some 7,000 members.
The sides would like to bring another Colombian armed leftist group, the National Liberation Army (ELN), into the peace deal.
But they have not managed to launch full peace talks with the group amid simmering mistrust between the government and the ELN, aggravated by ongoing violence.
Police said Wednesday that eight officers were injured in a bomb attack in the city of Cucuta, which they blamed on the ELN.