He warned that while the world's attention has been shifted to war in Gaza, the number of people fleeing their homes in Sudan had started to rise again.
As fierce fighting in Darfur once again pushes thousands of Sudanese to flee their homes, more must be done to alleviate the suffering of the millions already displaced, a UN official tells AFP.
"Six months and six million people forced to move, that's an average of one million per month, it's horrible suffering," said Mamadou Dian Balde, the top regional official for the UN's refugee agency (UNHCR).
The war between troops loyal to Sudanese army chief Abdel Fattah al-Burhane and the Rapid Support Forces (RSF) of General Mohamed Hamdane Daglo has left more than 9,000 dead since April, according to a UN report.
Of the nearly six million who have fled, 1.2 million have left the country, "very proud people who find themselves begging" and whose lives have been "totally disrupted," the UN official said.
He warned that while the world's attention has been shifted to the war in Gaza, the number of people fleeing their homes in Sudan had started to rise again, as RSF forces advance toward Nyala, the country's second city in the heart of Darfur.
Another UN official in the region, Dominique Hyde, said on social media Thursday she had witnessed "dramatic scenes at the border with Sudan.
"10,000 people seeking safety have arrived in the last three days," she said.
US Secretary of State Antony Blinken meanwhile said he was "deeply troubled" at information about an "imminent large-scale attack" by Sudan's paramilitary forces in El-Facher, the capital of North Darfur.
More and more people from Darfur are being pushed south, first to Chad in recent weeks and now to South Sudan.
Mamadou Dian Balde said the priority was for a cessation of hostilities, noting that ongoing negotiations in Saudi Arabia's Jeddah need to "succeed in stopping the fighting."
Talks between the warring parties resumed at the end of October. Previous attempts at mediation only resulted in brief truces, which were systematically violated.
In the meantime, "we must alleviate the suffering (of refugees) by providing resources to these people whose numbers are only increasing," he said.
The UN's humanitarian response plan in August called for around $1 billion in funding, anticipating a number of 1.8 million refugees by the end of 2023.
That plan has only received 38 percent of the funding required, while "the needs are growing," said the UN official, noting that most refugees were going to the most vulnerable parts of South Sudan and southern Chad, where local communities cannot absorb them.
That means the UN will need to build new camps.
"It's the last thing we want to do," said the UN official, but "we need to create new camps, because the populations are at the border" and in "extremely miserable conditions."
He also called for helping the local communities.
"We want development. We have to invest in these places because if we only give support to refugees, it will create tensions and tensions can translate into violence."