Rebels of the Revolutionary Armed Forces of Colombia, FARC, build a stage for the next day's ceremony that will commemorate the completion of the rebels' disarmament process, at the Mariana Paez demobilization zone, one of.
FARC was formed in 1964 as the military wing of Colombia's Communist Party.
"The mission received all individual arms of the FARC-EP according to the roadmap of May 29", the statement said Monday.
Officials say remnants of right-wing paramilitary groups are also fighting the ELN in rural areas for control of the drug trade that has fueled the conflict.
The weapons hand-over will be celebrated in a ceremony in Mesetas, in Meta province, on Tuesday.
Colombian President Juan Manuel Santos said FARC's disarmament would create a "peace that allows better education, health, housing and more opportunities for Colombians".
At the end of the ceremony, Londoño handed Santos a brass replica of an AK-47 to mark the end of his group's half-century long war with the Colombian state. They have to sign a pledge that they will never use weapons again.
The accord was at first narrowly rejected by Colombians in a referendum a year ago before it was redrafted and pushed through congress.
Critics such as conservative political leader Alvaro Uribe said the peace accord was too lenient on FARC members. Nearly every guerrilla at the Mariana Paez camp recalled the decade-long bloodletting that followed a previous attempt at peace in the 1980s, when as many 3,000 members of a FARC-aligned political party were gunned down by right-wing paramilitary assassins, sometimes in cahoots with state intelligence services.
The day put Colombia one step closer to turning a page on Latin America's longest-running conflict, which caused at least 250,000 deaths, left 60,000 people missing and displaced more than 7 million.
Santos says he wants to seal a "complete peace" by reaching a deal with the country's last active rebel group, the leftist National Liberation Army (ELN), which has some 1,500 members.
The ELN started talks with the government this year, though it has been blamed for ongoing confrontations with state forces.
Three women were killed in a bombing at a crowded shopping center in Bogota on June 17. The other weapons will be sealed in containers under the supervision of the United Nations. Those who do not face up to 20 years in jail.