By Alex Whiting

ROME (Thomson Reuters Foundation) - Farmers in drought-hit southern Africa urgently need help to plant the next harvest, or else the food crisis gripping the region will continue into 2017, the United Nations Food and Agriculture Organization said on Thursday.

Southern Africa has been badly affected over the past year by the El Nino weather pattern which has wilted crops, slowing economic growth and driving food prices higher.

Some 579,000 children will need treatment for severe hunger this year, and 23 million people urgently need aid, according to U.N. figures released earlier this week.

"If there is good support from (local) governments and the international community ... then we can break the cycle," Francesco Del Re, senior strategic adviser for drought response at the U.N. Food and Agriculture Organization (FAO), said on Thursday.

"If this doesn't happen you will have a continued crisis in 2017," he told the Thomson Reuters Foundation in a telephone interview from Johannesburg.

About 70 percent of the population depends on agriculture for their livelihoods. Many farmers have been forced to spend money on food rather than seeds and fertilisers, and to sell off their cattle.

"We have to help them (urgently) because the next planting season is a few weeks away," said Del Re.

The planting season begins in October, and the next harvest will be in February/March.

HIV TREATMENT INTERRUPTED

Children's futures are at stake, the International Federation of Red Cross and Red Crescent Societies (IFRC) said.

In some areas, they are missing out on school because they are too exhausted to attend, or have to seek work instead, or are being married off early, IFRC said.

Severe hunger can also stunt their physical and mental growth, and can stop them from reaching their full potential as adults.

"It's not a matter of they're hungry today and they won't go to school. This will impact them for the rest of their lives," Erin Law, health delegate for IFRC in Pretoria, said by phone.

The crisis is also affecting the region's response to the HIV virus, she added.

"We are at the center of the HIV epidemic in the world. We have children who ... cannot even access food to take their (HIV) medication," Law said.

"If we don't pay attention to this (crisis) now, this is going to cost a lot more, and be a lot worse in the future."

"THIS MUSTN'T HAPPEN AGAIN"

The El Nino drought has destroyed some 9.3 million tons of cereal, and hundreds of thousands of livestock, according to the U.N. Office for the Coordination of Humanitarian Affairs (OCHA).

At the same time, economic woes have compounded the effects of the drought. Currencies have been devalued, increasing the costs of food imports, and government revenues have been hit at a time when social safety nets need expanding, OCHA said.

Last month, the region's economic grouping, the Southern African Development Community (SADC), declared a regional drought disaster and launched an appeal for $2.4 billion.

Aid agencies also appealed for $1.2 billion to help 12.3 million people in the most-affected countries - Angola, Lesotho, Madagascar, Malawi, Mozambique, Swaziland and Zimbabwe.

El Nino, a warming of sea-surface temperatures in the Pacific Ocean, will be followed by La Nina, a weather pattern which brings higher than average rainfall.

This may improve harvests in southern Africa or, if it is severe, it may instead cause flooding and cyclones.

On average, El Nino happens every three to 10 years. FAO's Del Re said the region's rural communities need help to become more resilient to drought and floods, before the next El Nino phenomenon occurs.

This includes introducing drought-resistant crops, and government policies to do more to help vulnerable rural farmers, including helping them pay for drought insurance, he said.

"We have to make sure this (crisis) doesn't happen again," he said.

(Reporting by Alex Whiting, Editing by Ros Russell.; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, corruption and climate change. Visit http://news.trust.org)