The joint United Nations -African Union envoy for Darfur urged the Security Council on Monday to consider "stern measures" - likely sanctions - against Sudan Liberation Army founder Abdul Wahid Elnur, who has refused to join the peace process.Jeremiah Mamabolo told the Security Council that "from all accounts, he prefers belligerence and armed struggle to cessation of hostilities and a political process" and "it is highly unlikely that he would change this position any time soon."On a positive note, Mamabolo said Elnur's fighters declared a cease-fire for the first time from September 20 to December 18 to allow humanitarian access to areas in Jebel Marra affected by landslides. But it was broken two days later by Sudanese government forces, he said.Sudan's UN ambassador, Omer Dahab Mohamed, accused Elnur of showing disrespect to the Security Council by refusing to comply with its resolutions demanding that his rebel group end violence and engage in peace negotiations.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.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 Elnur in western and southern Jebel Marra.Mamabolo said by video from Johannesburg that elsewhere, the security situation remains "relatively calm and peaceful" with only "low-level intercommunal clashes" reported.Despite this progress, he said, the UN-AU mission in Darfur known as UNAMID has recorded an increase in tensions between herders and farmers - those displaced and those returning home - over land and resources. Displaced Darfuris remain concerned about "systematic attacks, assaults, farm destructions, harassment, land occupation issues and livestock theft," Mamabolo said.UN Secretary-General Antonio Guterres said in a recent report to the Security Council that the improving security situation and decrease in intercommunal violence and criminality reinforced the Security Council's decision in July to dramatically reduce the UNAMID forceIn June 2016, UNAMID had a ceiling of 15 845 military personnel and 3 403 police.The resolution adopted in July extended UNAMID's mandate until June 30, 2019, and ordered a gradual reduction to 4 050 troops by that date - a target Mamabolo indicated will be met along with abolishing the posts of 1 184 civilian members of the mission. The police ceiling will remain at 2 500.Guterres said UNAMID and UN agencies need to focus on peacebuilding, pursuing development activities outside Jebel Marra, and addressing the drivers of the conflict in Darfur."Much work remains to be done in this area, in particular with regard to the land issue, where the lack of a comprehensive solution continues to result in disputes over land ownership between internally displaced persons and herders who have occupied vacated lands," he said.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. The secretary-general stressed that "the issue remains a barrier to the return of internally displaced persons to their places of origin and an obstacle to peace."Guterres outlined specific benchmarks aimed at ending the UNAMID mission on June 30, 2020, and liquidating it by December 2020.Sudan's Mohamed said Guterres' approach builds on the 2011 Doha accords aimed at achieving peace with all rebel groups, and "we strongly support this approach.""The great improvement we've seen in the security and humanitarian situation in all states of Darfur since 2015 made it incumbent by the government, with support of the international community, to move Darfur from the phase of conflict to the phase of reconstruction, and to forge ahead with development efforts to solidify stability," he said.Mohamed said the government strongly backs a donor conference to help fund Darfur's reconstruction that was agreed to during last month's high-level General Assembly meeting.