The crisis, worsened by the 2023-2024 El Nino climate phenomenon, is expected to deepen until at least the next harvests due in March or April next year.

"Today we have up to 26 million people facing acute food insecurity in the region and this is because of El Nino induced drought," said Eric Perdison, regional director for southern Africa at the WFP.

The seven worst affected nations were Angola, Lesotho, Malawi, Mozambique, Namibia, Zambia and Zimbabwe, Perdison added.

Those need an additional $300 million to prevent access to sufficient, nutritious and affordable food worsening further, risking widespread hunger, according to the WFP.

Five countries -- Lesotho, Malawi, Namibia, Zambia, and Zimbabwe -- have declared a state of national emergency in the past months as the drought has destroyed scores of crops and livestock.

In many places, farmers who would normally be planting seeds at this time of the year, were not able to do so.

"If you travel across the country, you will see almost all empty fields... The situation is really really dire," said the WFP's country director in Mozambique, Antonella D'Aprile.

"Communities have very little or almost nothing to eat," she said, adding that "thousands of families are literally surviving on just one meal" a day.

Assistance "cannot wait," warned D'Aprile. "The time to support is really now."

- 'Brink' of hunger -

In neighbouring Malawi, the WFP said it has had to import food to provide assistance due to the shortages.

"Nearly half the maize crops were damaged by El Nino drought earlier this year," said the group's representative in the country, Paul Turnbull.

Families were facing grim choices, he said: "Skipping meals; adults not eating so their children can eat; withdrawing children from school; and selling anything they have of value."

Despite Zambia being "known as the food basket of southern Africa", the country "stands at the brink of a hunger crisis," said the WFP's director for the country Cissy Kabasuuga.

In Namibia, an upper middle-income country, the situation was also dire.

"All 14 regions were impacted by the drought, of which there are some that have very worrying levels (of food insecurity) and that's a very worrying situation for Namibia," said WFP's Tiwonge Machiwenyika.

The aid group's representative in the Democratic Republic of Congo (DRC) also joined the appeal for assistance.

The country has more than 25 million people facing emergency levels of food insecurity, said Peter Musoko, WFP's representative in the DRC, with "no relief in sight".

That was all "due to a cocktail" of conflict, climate extremes and health crises including outbreaks of mpox, cholera and measles, Musoko added.

As a result of those multiple issues, the WFP said it had also noted an increase in sexual and gender-based violence in the country and the opening of brothels around camps hosting displaced people.

US President Joe Biden on Tuesday during a trip to the region announced a $1 billion humanitarian aid package to 31 African countries, including for people affected by the drought.