U.N. relief coordinator John Holmes says one of the most severe droughts on record in southern Africa could turn into a serious humanitarian crisis if help is not forthcoming. VOA's Mona Ghuneim in New York reports, Holmes appealed to international donors for immediate aid during his news conference at the U.N. headquarters Tuesday.

Holmes says Zimbabwe's cereal harvest is expected to be 44 percent less this year than in 2006 because of the drought.

"The anticipation is that some 4 million people, which is around a third of the population, will be in need of some kind of food assistance by the first quarter of 2008," he explained.

Holmes says the drought is having an impact on Zimbabwe's already turbulent economy by driving food prices up in the markets. He also says the drought will undermine efforts to provide proper nutrition for the nation's large HIV/AIDS-infected population. Holmes estimates that population at 12 percent, but other experts place it even higher.

Holmes says he is especially concerned about Swaziland, where the government declared a national disaster last month. He says Swaziland has one of the highest rates of HIV/AIDS cases in the world. One-fifth of the population, or 220,000 people, he says, suffers from the epidemic. 

"That means there's a lot of orphans, a lot of children under five, who are particularly vulnerable so there are great worries about severe malnutrition if we don't act now," he added.

Holmes says the aid priorities for the region are food and agriculture, health and nutrition, and water and sanitation. He says early recovery is possible but only if the international community acts at once.