The United States warned Tuesday of severe food shortages in Zimbawe this year, challenging government forecasts of a bumper corn harvest. The State Department says it is concerned about political manipulation of the food supply system in the African country.

Zimbabwe's President Robert Mugabe says his government's controversial land-reform program will help produce a corn crop this year some three times as large as the one in 2003.

But the State Department says United Nations and other independent estimates of the crop are far smaller, and it is expressing concern that the Mugabe government may be trying to manipulate the food distribution system for political ends.

At a news briefing, State Department spokesman Richard Boucher said the United States is very concerned about the food situation in Zimbabwe and is expecting severe shortages, despite the government's forecast of a two-point-four million ton corn harvest.

The spokesman said the official prediction from Harare differs greatly from the U.N. Food and Agriculture Agency's estimate of only 950-thousand tons of corn and said the U.N. figure is more in line with other estimates.

He suggested the government may be inflating its forecasts in order to prompt the U.N.'s World Food Program and other relief agencies to fold their operations in Zimbabwe and leave the government with a monopoly on food distribution:

"We have found the government (to be) trying to curtail donor activity and engagement in Zimbabwe. We've been deeply concerned the Mugabe government is using its monopoly on food distribution to manipulate food availability for political ends, and that there needs to be another track of food distribution available to people," he said.

The Washington Post reported Tuesday that despite evidence of continued widespread need, the World Food Program, obliged to accept official crop estimates, was dismantling the distribution network it had set up in Zimbabwe over the last few years.

It said the Mugabe government views international aid groups as a threat to its rule, and had used food supplies as a political tactic, rewarding government supporters with food allotments and withholding them from opponents.

Though the country was a food exporter as recently as four years ago, harvests in Zimbabwe have plummeted due to drought and a land reform program U.S. officials say has driven white commercial farmers out of the country and left their former holdings in the hands of Mugabe associates with little farm expertise.

The United States has been a major contributor of food aid to Zimbabwe despite its political differences with the Harare government. Mr. Boucher said the Bush administration is prepared for a "rapid and effective response" to 2004 needs that could approach those of last year, when five million people in Zimbabwe needed outside aid.