The Colombian government on Wednesday, 4 January, said the United Nations should maintain its neutrality after a video of its officials dancing with the Revolutionary Armed Forces of Colombia (Farc) at a New Year celebration went viral.

In a letter, President Juan Manuel Santos's government asked the UN observers, who are tasked with supervising the demobilisation of leftist guerillas, to safeguard their objectivity.

Maria Emma Mejia, Colombia's ambassador to the UN, said in the publicly issued letter that the video was a source of "great worry and surprise". It was filmed by Spanish news agency EFE during a party inside the Colombian jungle camp and showed two men, wearing blue vests with the UN insignia, dancing with female guerrillas from the Marxist Farc movement.

"This type of behavior distorts the professionalism and neutrality that should characterize, at all times, the team that is part of the tripartite mechanism for the monitoring and verification of the ceasefire and definitive laying down of arms," the letter said.

It also mentioned that the global body should make sure such incidents are not repeated so as to maintain people's faith in the organisation.

The UN has also said the conduct of the staff shown in the footage was "inappropriate and doesn't reflect the values of professionalism and impartiality of the mission".

Farc, meanwhile, said the reactions to the video are exaggerated.

"Let's leave behind the hatred and get in step with peace and reconciliation," Farc leader Rodrigo Londono, popularly known as Timochenko, tweeted on Wednesday, adding the hashtag "I dance for peace".

At present, at least 280 UN personnel are working in Colombia as part of the demobilisation mission.