Agriculture Minister Mundia Sikatana in June banned imports of GM maize, arguing that its safety was not known and Zambia could not risk the lives of its people.

The WFP and its sister body, the U.N. Food and Agriculture Organisation, estimate some 13 million people in Malawi, Zimbabwe, Zambia, Mozambique, Lesotho and Swaziland need about 1.2 million tonnes of food up to March next year after bad weather and political mismanagement slashed food output.

Some 2.3 million Zambians will need about 174,000 tonnes of food between now and March, the two organisations estimate.

Ragan said the WFP could buy maize from Canada, Argentina, China or the United States, adding the WFP would settle for a cheapest source.

"GM maize in the U.S. costs about $90 per tonne and shipment is around $100 per tonne from the U.S. to Zambia. White maize in South Africa (the nearest market for Zambia) will cost around $260 per tonne, so we have to settle for the cheapest," he said.

South Africa produces limited quantities of genetically altered maize and nearly all its white maize, a staple in many southern African diets, is GM free.

The Zambia National Farmers' Union (ZNFU) Chairman Ajay Vashee told Reuters that Zambian farmers required 40,000 tonnes of yellow maize to feed livestock and would be prepared to use GM maize even though it could harm meat exports.

"We have no option as a country but to use GM maize. We neither know the dangers nor the safety of GMO (genetically modified organism) foods, but people in the United States are eating the GMO foods and no one has died," Vashee said.

Vashee said Zambia's poultry and dairy exports to the United Kingdom, which does not import GMO foods, would slump. He did not have export figures.

"Since not all farmers will use GM maize for their livestock, we have to label our products to indicate if GM maize was used to feed them or ordinary stock feed was used," he said.