"Hostilities have intensified in recent weeks. While both warring parties have declared a readiness to negotiate a ceasefire, their actions on the ground suggest otherwise," Pobee told the Security Council members during a meeting on Sudan.
She went on to say that no ceasefire was reached in Sudan during the last round of talks in Jeddah.
"Regrettably, the parties did not reach an agreement on a ceasefire in this round of Jeddah talks. Instead, they have intensified the fighting," Pobee added.
Civilians need to be big stakeholders to the future agreement to function, she stated.
Pobee said that people fleeing from West Darfur to Chad are reporting "technically-driven" violence against particular communities.
In April, violent clashes broke out between the Sudanese army and the Rapid Support Forces (RSF) paramilitary group. The parties to the conflict have since introduced a number of temporary nationwide ceasefires, but none has helped settle the conflict.
In late October, the parties resumed negotiations, mediated by Saudi Arabia. The UN estimates the death toll from the conflict in the hundreds.