President Robert Mugabe said a U.S. diplomat who said government policies were to blame for Zimbabwe's crisis could "go to hell."

U.S. Ambassador Christopher Dell last week blamed Mugabe's policies, rather than the drought and Western-imposed sanctions and boycotts Zimbabwe officials often blame, for 80 percent unemployment, 359 percent inflation, and an escalating humanitarian crisis.

"Mr. Dell, go to hell," state radio quoted Mugabe as saying Tuesday.

Dell angered Mugabe with a speech last week in which he said that gross mismanagement and corruption had wrecked the once prosperous economy. He also challenged the government to admit that the demolition of thousands of homes, shacks and market stalls earlier this year had left a humanitarian crisis despite Mugabe's refusal to accept U.N. aid.

Zimbabwe last month accused Dell of trying to provoke a diplomatic standoff after he entered a restricted area near one of Mugabe's residences. He was held at gunpoint for 90 minutes by the presidential guard as he walked his dog through the National Botanical Gardens, apparently not realizing it was off limits.

The United States has been among Mugabe's sharpest critics. U.S. Secretary of State Condoleezza Rice once labeled Zimbabwe an outpost of tyranny.

Zimbabwe's economy has been in a tailspin since the government began its policy in 2000 to confiscate formerly white owned farms. This has decimated agricultural production in what used to be southern Africa's breadbasket.

U.N. agencies say 4.2 million Zimbabweans, mostly in rural areas, urgently require food relief to survive to the next harvests due in April 2006.