The United Nations will hold a meeting on the growing humanitarian situation in war-torn South Sudan, official said.

The Special Representative of UN Secretary-General to South Sudan, Mr David Shearer, said in a statement on Thursday that the September 20 meeting would assess the current humanitarian situation.

The objective of the meeting, the statement explained, was to draw attention to the humanitarian crisis in South Sudan and to mobilise international support to mitigate it.

A recent report by the UN Office for Humanitarian Affairs said the number of people displaced in South Sudan rose to nearly four million during the first half of this year.

The figure includes 1.9 million people who have been internally displaced and two million others who have fled to neighbouring countries – one million in Uganda alone.

The report said the total number of people in real need of aid in South Sudan had risen to 7.6 million.

Mr Shearer said a lot of money would be required to reach all the people currently in need of aid in South Sudan with food, health care and education support.

"The current humanitarian response plan is budgeted at $1.64 billion. So far, 66 per cent of that funding has been received," Mr Shearer said.

He further lamented the insecurity facing the aid workers in South Sudan, saying it was a major impediment to their operations.

"I am sure the events in New York will also highlight the importance of ending impunity for attacks against civilians and humanitarian workers," he said.

READ: World Bank gives S. Sudan $50m humanitarian aid

Last week, a driver for the International Committee of the Red Cross (ICRC) was killed when a relief convoy was attacked in the opposition-held territory in Western Equatoria. That brought to 18, the number of aid workers who have been killed in South Sudan in 2017.