The United Nations says poor harvests across much of southern Africa mean that nearly 30 million people will struggle to get adequate nutrition in the months ahead.

U.N. agencies said in a statement Monday that "food insecurity" will be most acute in Malawi, Zimbabwe and Madagascar, which suffered extreme crop failures because of drought. They say there are also food concerns in Lesotho and the southern parts of Angola and Mozambique.

The U.N. Food and Agriculture Organization and the World Food Programme say they plan to step up assistance, citing data that show there will be about 27.4 million people facing food insecurity in the region in the next six months.

The agencies define food insecurity as struggling to "buy or produce enough nutritious food to lead a healthy life."