Over one million people have now fled the Sudanese war into neighbouring South Sudan, according to the United Nations, which said the figures illustrated the scale of the unfolding humanitarian crisis.
Tens of thousands have been killed and more than 12 million forced from their homes since conflict erupted between Sudan's army and a rival paramilitary group in April 2023.
More than 770,000 people have fled through the Joda border crossing in the last 21 months, while tens of thousands more have crossed into South Sudan elsewhere, bringing the total to more than a million, according to new UN data on Tuesday.
Most of the million people crossing the border are South Sudanese nationals who had previously fled from civil war in the world's newest country, UN refugee agency UNHCR said in a statement.
"The arrival of over a million people into South Sudan is a stark and sobering statistic and truly shows the increasing scale of this crisis," the UNHCR's Sanaa Abdalla Omer said.
"The people of South Sudan continue to show extraordinary generosity, welcoming those in need and sharing what little resources they have, but they cannot shoulder this massive responsibility alone."
The joint UN statement called for more support for both displaced people and the communities hosting them, warning that resources in South Sudan such as healthcare, water and shelter had become "dangerously overstretched".
Two transit centres in Renk county on South Sudan's northern border were designed for fewer than 5,000 people but were now hosting over 16,000, the statement said.
Last week, 16 Sudanese nationals were killed in South Sudan after anti-Sudanese protests degenerated into looting and violence, according to police.
Sudan is suffering the world's worst internal displacement crisis and famine has been declared in parts of the country.
The war has pitted Sudanese army chief Abdel Fattah al-Burhan against his former deputy Mohamed Hamdan Daglo, who commands the paramilitary Rapid Support Forces (RSF).
Both sides have been accused of war crimes, including targeting civilians and indiscriminately shelling residential areas.
The RSF has been specifically accused of ethnic cleansing, systematic sexual violence and laying siege to entire towns.
Research in November that took into account deaths from all causes, including disease and starvation, estimated that more than 61,000 people died during the first 14 months of the war.