The UN representative to Sudan, Volker Perthes, has announced his resignation.
Mr Perthes warned the UN Security Council that the situation in Sudan, which broke out in April between opposing military factions, ran the risk of devolving into a full-fledged civil war.
It comes more than three months after Sudan declared him unwelcome after the war erupted.
Five million people have been displaced in the clashes between the Sudanese armed forces and the rival paramilitary forces, the Rapid Support Forces (RSF).
In his final speech to the Security Council, Mr Perthes was extremely critical of Sudan’s military ruler, Gen Abdel Fattah al-Burhan and the RSF chief Gen Mohamed Hamdan Dagalo better known as Hemedti.
Mr Perthes said the two leaders chose to plunge the country into a war that is leaving a tragic legacy of human rights abuses. He blamed the RSF for the sexual violence, looting and killings in areas it controls.
He also chastised Sudan’s military forces for their indiscriminate aerial bombings.
Medics in the Darfur city of Nyala were dealing with the consequences of yet another atrocity as he spoke. Air strikes killed forty people there, adding to the more than 50 slain on Sunday.
The RSF fighters are embedded in densely populated urban centers, which appear to be legitimate targets for the Sudanese military.
