Part of a 2016 peace deal with the FARC, the move is a key part of efforts to end the conflict.
PIC: FARC rebels stay at the Transitional Standardization Zone Mariana Paez, Buena Vista, Mesetas municipality, Colombia before the final ceremony of abandonment of arms and the FARC's end as an armed group. (AFP)
Colombia's leftist FARC rebel force celebrates its disarmament on Tuesday after half a century of war against the state, ending Latin America's oldest civil conflict.
FARC leader Rodrigo Londono, alias Timochenko, is scheduled to formally conclude the disarmament process at a ceremony with President Juan Manuel Santos in the central town of Mesetas at 1500 GMT.
Part of a 2016 peace deal with the FARC, the move is a key part of efforts to end the conflict. But the process has been blighted by ongoing violence involving other armed groups in recent weeks.
United Nations monitors said they "have the entirety of the FARC's registered individual arms stored away," except for some that were exempted for transitional security at demobilization camps until August 1.
Separately, the UN mission is continuing to extract and destroy other weapons and munitions stashed in remote hiding places which the FARC have identified and surrendered to the monitors.
Londono called the disarmament "a historic moment for Colombia," ahead of Monday's UN announcement.
"The laying down of arms is an act of will, courage and hope," he wrote on Twitter.
Santos said last week that the event "changes the history of Colombia."
"The FARC, the most powerful and oldest guerrilla force in Latin America, will cease to exist," he said in a speech in Paris.
The former fighters are now due to make the transition into civilian life. The Revolutionary Armed Forces of Colombia (FARC) will transform into a political party.
Weapons "fulfilled a function at one time, but today we are making a political decision and we no longer need them," senior FARC commander Mauricio Jaramillo told AFP.
The accord, first signed in November, was initially narrowly rejected by Colombians in a referendum before being redrafted and pushed through congress.
Critics such as conservative political leader Alvaro Uribe said it was too lenient on FARC members, some of whom will get amnesties or reduced sentences for crimes committed during the conflict.
Colombia's civil conflict erupted in 1964 over land rights. It drew in leftist guerrillas, right-wing paramilitary groups and state forces.
It has left 260,000 people confirmed dead, more than 60,000 missing and seven million displaced.
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).
The ELN started talks with the government in February, but has been blamed for ongoing confrontations with state forces.
The ELN kidnapped two Dutch journalists on June 19 and freed them five days later.
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.
Three women were killed in a bombing at a crowded shopping center in Bogota on June 17. That was blamed on a fringe extremist group, the Revolutionary People's Movement (MRP).