Updated

The Security Council unanimously approved a resolution Friday that will dramatically cut the United Nations-African Union military force in Sudan's vast western Darfur region by more than half in response to reduced fighting and improved security conditions.

The resolution adopted by a vote of 15-0 also looks ahead to "the eventual exit" of the joint force known as UNAMID.

The Darfur conflict began in 2003 when ethnic Africans rebelled, accusing the Arab-dominated Sudanese government of discrimination. The government in Khartoum was accused of retaliating by arming local nomadic Arab tribes and unleashing them on civilian populations — a charge it denies.

The U.N.-AU force was established in 2007 with a mandate to help protect civilians in Darfur.

In recent years, as the result of a successful government military campaign, the rebellion has been reduced to rebel Sudan Liberation Army forces loyal to founder Abdul Wahid Elnur in western Jebel Marra.

The resolution welcomes the improvements in security conditions and the reduction in military confrontations between government forces and rebel groups. But it expresses concern that the situation still "remains precarious" due to destabilizing activities of some armed movements and "auxiliary units" of Sudanese government forces and militia groups.

The council said inter-communal conflicts over land, access to water and other resources, migration issues and tribal issues have significantly decreased but remain "one of the main sources of violence in Darfur."

U.N. peacekeeping chief Jean-Pierre Lacroix told the council last month that the situation in Darfur "has changed radically for the better" and the U.N. and AU were recommending major cuts.

In June 2016, UNAMID had a ceiling of 15,845 military personnel and 3,403 police. It was reduced significantly at the end of January.

A recent U.N.-AU strategic review recommended a further sharp reduction from the current 8,735 troop ceiling to 4,050 military personnel and from 2,500 to 1,870 police officers.

The resolution adopted Friday extends UNAMID's mandate until June 30, 2019 and orders a gradual reduction to 4,050 troops by that date "unless the Security Council decides to adjust the scope and pace of the reduction." But it keeps the international police force at the current ceiling of 2,500.

According to U.N. diplomats, during negotiations on the resolution some countries including Russia, China and Ethiopia supported reductions in the troops and police, but other council members thought they were too severe so as a compromise the police force was kept at its current level.

The council said the reduction in military personnel "should prioritize the retention of the highest performing contingents."

Sudan's government, stressing the reduction in fighting, has called for UNAMID to be wrapped up. The United States has also been pushing for major cuts to U.N. peacekeeping operations.

The Security Council said Secretary-General Antonio Guterres' initial report in 90 days on implementation of the resolution should include "a detailed and clearly benchmarked exit strategy for UNAMID."

It said this should focus particularly on the benchmarks and indicators Sudan's government has responsibility for in the areas of protecting civilians, reforming the security sector, ensuring rule of law and human rights.

The council also called on UNAMID and U.N. officials in Sudan "to identify ways to address gaps in capabilities to prepare for the mission's exit."