It is estimated that more than 600,000 Rohingya have fled to neighbouring Bangladesh to escape the violence which has been escalating since the summer.
The United Nations human rights chief, Zeid Ra'ad al-Hussein, said in Geneva on Tuesday that Burmese security forces may be guilty of genocide, adding worldwide pressure on Myanmar to be investigated for crimes against humanity.
Zeid said actions by Myanmar's government to "dehumanize" the Rohingya minority were likely to fan more violence and affect more communities across the region.
He told a special session of the Human Rights Council on the Rohingya on Tuesday: "My government is doing everything possible to deter these extremist acts".
The refugees have fled a military operation in which security forces and Buddhist mobs have killed men, women and children, looted homes, and torched Rohingya villages.
Trump hopes to avoid government shutdown in meeting with lawmakers: White House
But there are still sticking points among Republicans in the House and Democrats in the Senate, and time is running short. That would give bargainers time to work through their disagreements, but they will need Democratic votes to succeed.
MrZeid said no Rohingya should be sent back unless there was sustained human rights monitoring on the ground. Two delegations in the 47-member council were not present.
We will remind, recently in Bangladesh, wild elephants attacked the refugee camp of Muslim Rohingya, killing four people.
Marzuki Darusman, head of an independent worldwide fact-finding mission on Myanmar, said by video from Malaysia: "We will go where the evidence leads us".
The leader of a United Nations -mandated fact-finding mission for Myanmar say it's examining "in depth" allegations that genocide or crimes against humanity have been committed against the Rohingya. They include indiscriminate shooting and stabbing of villagers, rape, beatings and the burning of houses with families inside.
Addressing the Human Rights Council on Tuesday, Zeid said United Nations investigators have received "concordant reports of acts of appalling barbarity committed against the Rohingya" during a military crackdown in Rakhine state in August. He said that further efforts were needed to ensure the early return of the Rohingya refugees in an acceptable environment of safety and dignity to their ancestral homes in Myanmar.