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, the AP recalls.