More than 70 per cent of the number in Uganda (about 572,000) arrived since July last year and given present rate of arrivals, the figure could surpass one million by the middle of 2017.

“We are at breaking point” warned Filippo Grandi, the United Nations High Commissioner for Refugees, appealing for urgent and massive support.

“The lack of international attention to the suffering of the South Sudanese people is failing some of the most vulnerable people in the world when they most desperately need our help.”

According to the Office of the UN High Commissioner for Refugees (UNHCR), Uganda’s approach to dealing with refugees has long been among the “most progressive” anywhere on the African continent but the sheer scale of the influx has placed enormous strain its services and infrastructure.

“Uganda has continued to maintain open borders,” said Ruhakana Rugunda, the Prime Minister of Uganda, adding: “We continue to welcome our neighbours in their time of need but we urgently need the international community to assist as the situation is becoming increasingly critical.”

Chronic and severe underfunding has reached the point where critical programmes operated by UNHCR are at the risk of being dangerously compromised.

Transit and reception facilities are rapidly becoming overwhelmed and there are significant challenges in providing adequate food rations, health and educational services, as well as sufficient clean water.

The already dire situation has been further complicated by the onset of heavy rains.

The UN agency is in urgent need of more than $250 million to support South Sudanese refugees in Uganda in 2017.

There are clear risks that the severe underfunding in what has become the fastest-growing refugee emergency in the world is jeopardizing a model that allows refugees to thrive now.

“Uganda cannot handle Africa’s largest refugee crisis alone,” said Grandi, calling on the international community to keep the future of the new comprehensive refugee response framework from being thrown into question.