The United States renewed its criticism of Zimbabwe's government Wednesday, the eve of a deadline by which thousands of white farmers are to vacate their property under a controversial land-reform program. It says the policies of President Robert Mugabe have plunged the country into economic chaos.

The State Department said the United States is not opposed to "reasonable" land reform in Zimbabwe, where white farmers have controlled the most fertile lands since the British colonial era.

However it says the Mugabe government's version of reform, which it said has featured violent seizures of commercial farms, is contributing to food shortages that have put half the country's population at risk of famine.

A law pushed through Zimbabwe's parliament in May requires that nearly three-thousand white farmers vacate their property by midnight Thursday local time, when a government deadline for farm takeovers expires.

At a briefing here, State Department spokesman Philip Reeker said Mr. Mugabe's "corrupt" regime and what he termed "its dismissal of standard democratic norms" have taken a country that should be prospering, and plunged it into economic "chaos and ruin."

"Up to six million people, half of Zimbabwe's population, are at risk due to the food shortages in that country, even though the country should be a bread basket. And with the severe drought, which has undoubtedly been a factor, certainly the policies and actions of Mugabe's government have exacerbated the situation. Shortfalls in agricultural production in Zimbabwe due to, in large part, the government-sponsored, chaotic and often violent seizures of commercial farms and failed economic policies are having a direct impact on food availability and prices, not just in Zimbabwe but throughout the region," Mr. Reeker said.

Mr. Reeker said Mr. Mugabe needs to reexamine his policies in terms of land seizures and go back, as he put it "to the road to democratic norms that Zimbabwe should be on."

The Bush administration was sharply critical of the Harare government's conduct of elections in March which gave Mr. Mugabe another six-year term in office, calling the vote "fundamentally flawed."

It joined the European Union at that time in imposing financial and travel sanctions on Mr. Mugabe, his closest associates and family members.

While maintaining food supplies to Zimbabwe, the United States has more recently accused the government of politicizing the distribution of relief supplies in some areas.