Dissident former Revolutionary Armed Forces of Colombia (FARC) rebels kidnapped Arley Lopez, a Colombian national working on a coca substitution project in the southern state of Guaviare on Wednesday evening. He was stopped by armed men in a convoy of vehicles.

The UN "condemns the events that happened yesterday in Guaviare and that go against the integrity and rights of a colleague in the United Nations Office on Drugs and Crime and demand his immediate liberation," it said in a statement. Colombian army and police began searches to find Lopez.

The government in Bogota also condemned the kidnapping, which it described as "regrettable."

Colombia's High Commissioner for Post-Conflict, Rafael Pardo, told Caracol Radio the rebel group had indicated it would release Lopez on Thursday. UN officials in coordination with Colombian authorities were attempting to negotiate his release.

The government is carrying out a program to substitute the raw material for cocaine, coca, with legal crops such as coffee, fruits and cacao.

"These people live thanks to drugs and they want to continue living that way," said Rodrigo Pardo, the Colombian president's top aide for post-conflict planning who confirmed the kidnappers were a FARC unit who refused to lay down their weapons as part of a peace deal last year.

UN Security delegation

President Juan Manuel Santos met Thursday with the ambassadors to the UN Security Council who were visiting to show their commitment to endingthe war which lasted 50 years and caused 220,000 deaths while displacing nearly six million people.

Co-leader of the delegation, British Ambassador Matthew Rycroft, said the UN would remain in Colombia for as long as it took to secure peace.

"Colombia has started this process and it is already an irreversible process, there is no turning back and the Security Council will remain by your side as long as it takes," Rycroft confirmed to his hosts in Bogota.

The Colombian military said that up to 7,000 former rebels had agreed to the peace deal and were in the process of turning in their weapons but several hundred had refused. They have been accused of forming criminal gangs and engaging in lucrative, illegal drug trafficking.

US President Donald Trump is to host President Santos in Washington on May 18 to discuss the implementation of the peace accord as well as efforts to counter "democratic backsliding in Venezuela," according to the White House.

Deadline for weapons

Rebels only have a few weeks left in order to hand over weapons, according to last year's peace treaty schedule. Although in a radio interview, FARC leader Ivan Marquez said this week that the two sides could extend the May 31 deadline to complete the demobilization process. He said that the rebels would not turn over their arms until the government followed through on its commitment to free hundreds of jailed rebels subject to an amnesty.

Some 450 UN observers are present in more than 20 rebel camps nationwide to oversee the weapons handover.

jm/bw (EFE, Reuters, AP)