The East African region could be on the verge of a food crisis if huge swarms of locusts devouring crops and pasture are not brought under control.
A massive food assistance may be required, Dominique Burgeon, director of emergencies for the UN’s Food and Agriculture Organisation (FAO), said.
Ethiopia, Somalia, Kenya, Tanzania and Uganda are affected.
Efforts to control the infestation have so far not been effective.
Aerial spraying of pesticides is the most effective way of fighting the swarms but countries in the region do not have the right resources.
There are fears that the locusts – already in the hundreds of billions – will multiply further.
The FAO says the insects are breeding so fast that numbers could grow 500 times by June.
The UN body has now called on the international community to provide nearly $76m (£58m) to fund the spraying of the affected areas with insecticide.
“If it doesn’t, the situation will deteriorate and then you will need to provide massive food assistance for a humanitarian situation that may even get out of control,” Mr Burgeon said.
“There is always a risk when you have people in acute food insecurity that famine is not very far,” he added.
An FAO spokesperson later clarified that they were not warning about a famine but rather “food insecurity”.