Food rations have successfully reached about one million people displaced by fighting in the Sudanese region of Darfur, the United Nations says.
Food supplies are only guaranteed until September
Despite the rains and continued insecurity, the World Food Programme (WFP) distributed 15,000 tons of food last month, an improvement on June.
But tens of thousands of people in inaccessible places still urgently need food, said the WFP's Peter Smerdon.
Under-funding means food supplies are only guaranteed to September, he said.
"We need more support... we have received just over $100m... and we believe it will cost us at least $195m to keep operating for the entire year," Mr Smerdon told the BBC's Focus on Africa programme.
In what is described as the world's worst humanitarian crisis, the UN says up to 50,000 people have died since the conflict erupted last year.
Insecurity in Darfur remains a problem especially along the road between Nyala and Ed Daein, Mr Smerdon said.
On two occasions four trucks were looted by people who said they were members of the rebel Sudan Liberation Army (SLA), he said.
"These people were dressed in civilian clothes but said they were members of the SLA. They took the food from the truck and let the trucks go on."