The United Nations World Food Programme (WFP) said on Tuesday it had suspended some food aid in South Sudan due to a funding shortage - heightening the risk of starvation for 1.7-million people.

The move to suspend aid to almost a third of the 6.2-million people in South Sudan the WFP had planned to assist this year comes as global food prices soar amid the Russia-Ukraine war, leaving humanitarian agencies with funding shortfalls.

Climate change is also exacerbating the situation, with South Sudan facing severe flooding, localised drought as well as man-made conflict that has left more than 60% of the population grappling with severe hunger.

"South Sudan is facing its hungriest year since independence. We are already in a crisis, but we are trying to avert the situation from becoming more explosive," the WFP's acting country director in South Sudan, Adeyinka Badejo-Sanogo, told reporters in Geneva.

Badejo-Sanogo, who was speaking from Juba, South Sudan's capital, said the WFP urgently needs $426-million to cover needs for the next six months and dial back what she described as an "explosive situation".

The WFP said it had exhausted all options before suspending food assistance, including halving rations in 2021.

It said that following the food aid suspension, it is now hoping to reach 4.5-million South Sudanese in need, including 87 000 people already experiencing famine-like conditions.