Nearly 13 million people in six countries - Lesotho, Malawi, Swaziland, Zambia, Zimbabwe and Mozambique - face starvation from drought and disease, which have devastated crops.

Zambia, where 2.4 million people face starvation, has refused large shipments of biotech food aid until its scientists can determine the foods are safe for human consumption. The head of the U.N. World Food Program said last week the controversy could soon halt aid distributions in Zambia.

"Now is not the time to inflame the debate about biotechnology," Veneman said. "Now is the time to feed starving people."

The United States is the world's largest producer of crops that are genetically modified to make them resistant to pests or to withstand herbicides that kill nearby weeds. Washington is providing half of all food aid to southern Africa.

African nations fear domestic farmers would plant the biotech crops in their fields, jeopardizing farm exports to Europe, which has strict standards on genetically modified food.

Zimbabwe, which has also resisted U.S. food shipments, agreed last week to accept 17,000 tonnes of U.S. corn, which will be milled to prevent any chance of contaminating the country's domestic crops.

Green groups have long campaigned against the use of genetically modified foods, saying not enough research has been done to ensure the new technology was safe for the environment and public health.

Veneman said these groups have "greatly hindered" food aid efforts by providing "misguided statements about the U.S. food system."

Veneman's unusually strong statements follow similar criticism expressed by Andrew Natsios, administrator of U.S. Agency for International Development, last week.