UN Secretary-General Ban Ki-moon addresses a High-level Event on the Entry into Force of the Paris Agreement at the UN headquarters in New York, on Sept. 21, 2016. (Xinhua/Li Muzi)

UNITED NATIONS, Sept. 21 (Xinhua) -- UN Secretary-General Ban Ki-moon on Wednesday commended the UN Security Council for its "unanimous, timely and effective action" when the 15-nation UN body was requested by Colombia to help promote the peace process in the Latin American country.

"I commend the Security Council for its unanimous, timely and effective action in responding to Colombia's request for assistance," the secretary-general said at an open council meeting on Colombia. "When the parties asked for this support in January, there was still no ceasefire, much less a final agreement. Yet the Council did not hesitate."

"You believed in the Colombian peace process and you acted," Ban told the council.

"The international community has been privileged to support your efforts," the secretary-general said. "I would like to recognize in particular the contributions of Cuba and Norway, the guarantors, along with Chile and Venezuela, the accompanying nations."

"The United Nations has been entrusted with important responsibilities, in particular in the monitoring and verification of the ceasefire and the laying down of arms," he said.

Also on Wednesday, Colombian President Juan Manuel Santos Calderson told the UN General Assembly that the war in Colombia, the world's longest conflict, has ended, and the peace agreement will be officially signed on Sept. 26.

"We are now well advanced in the deployment of the UN Mission in Colombia," the secretary-general said.

Some 200 unarmed UN observers and civilian staff are on the ground, deploying to the zones where they will carry out their verification, working with the parties, and engaging with communities and local authorities, Ban noted. "Their numbers will grow quickly as the next stages of the peace process are completed. Their presence aims to help ensure that crucial commitments will be kept and to build confidence in the peace process."

On Aug. 24, the negotiators from the Colombian government and the Revolutionary Armed Forces of Colombia- Peoples' Army (FARC-EP) declare in Havana, Cuba, that they adopted the final text of the Agreement for the Termination of the Conflict.

Four years ago, the Colombian government and the FARC set out to resolve one of the world's oldest armed conflicts through dialogue.

The conflict between the Colombian government and the leftist rebel group started in the 1960s as an uprising for land rights. It has left about 260,000 people dead, 45,000 missing and nearly 7 million displaced, according to official figures.