The UN Security Council is expected to approve a draft resolution on Monday that calls for establishing a UN mission to oversee disarmament should Colombia's government and leftist FARC rebels reach a final peace deal, diplomats said.
The UN press office said on Sunday the council was scheduled to discuss Colombia at 3 pm (2000 GMT) on Monday. Several council diplomats said a draft resolution Britain circulated to the 15-nation body on Thursday would be put to a vote during that meeting.
Speaking on condition of anonymity, the diplomats said on Sunday they expected the resolution to be adopted unanimously.
Colombia's government and FARC agreed on Tuesday to ask the council to help monitor and verify rebel disarmament should the two sides reach a deal to end their 50-year-old war.
The text, drafted by Britain and seen last week by Reuters, would have the council "establish a political mission to participate for a period of 12 months ... to monitor and verify the definitive bilateral ceasefire and cessation of hostilities, and the laying down of arms."
To begin the process of creating the mission, it would ask Secretary-General Ban Ki-moon "to initiate preparations and to present detailed recommendations to the Security Council for its consideration and approval." It said he would submit his recommendations within 30 days of the signing of a peace deal.
It added that the council would establish "a political mission of unarmed international observers" and welcomed the willingness of members of the Community of Latin American and Caribbean States to contribute personnel.
Colombian President Juan Manuel Santos said last year he would make such an appeal to the United Nations.
Santos, who staked his 2014 re-election on the peace talks, has been pressing for a deal to end Latin America's longest war, which has killed 220,000 and displaced millions since 1964.
The rebels' willingness to make the request jointly with the government is a sign of progress as the two sides aim to reach a comprehensive peace agreement before a March 23 deadline that negotiators set last year.
In addition to verifying a bilateral ceasefire and presiding over the FARC's disarmament, the international monitors would settle any disputes and make recommendations.