A serious drought has left parts of Somalia at risk of famine and 320,000 children are already severely malnourished and in need of care, the UN humanitarian agency said Tuesday.

"The level of humanitarian suffering in this country triggered by projected conflict, seasonal shocks and disease outbreaks are typically hard to bear, but the impact of this drought represents a threat of a different scale and magnitude," said Peter de Clercq of the agency UNOCHA.

Somalia is one of several East African nations, including South Sudan, Ethiopia and Kenya, suffering from two failed rainy seasons, leading to food shortages and the death of livestock across the region in what some have said is the worst drought in over five years.

"Expanding drought conditions have left hundreds of thousands of Somalis facing severe food and water shortages. Overall, some five million people are in need of humanitarian assistance," said de Clercq.

The humanitarian community in Somalia is seeking $864-million (800 million euros) for its operations in 2017, to "avert catastrophe" from the drought.

Famine early warning system FEWSNET warned Monday that if 2017 rains were again poor in Somalia -- as forecast -- "famine would be expected."

However concerns are even higher for conflict-torn South Sudan, where fighting has compounded the fallout from the drought, and few humanitarian organisations remain.

In Kenya, the drought has led to a rise in conflict between pastoral communities looking to graze their animals, while roaming wildlife are coming into conflict with humans as they seek new water sources.

Nairobi, East Africa's economic hub, is under strict water rationing for four months, when the next rainy season is expected to start.