Foreign Minister Mustafa Osman Ismail, who is visiting South Korea to promote trade, also condemned Powell's call for the United Nations to consider economic sanctions against Sudan.
He accused the United States of focusing on Sudan in order to divert the attention of American voters from fighting in Iraq ahead of the U.S. presidential election in November.
"This is a politicized agenda for the election," said Ismail.
"It would be very difficult for the U.S. or the Security Council of the United Nations to pass any sanctions on Sudan," he said, citing opposition from some countries in the U.N. Ismail urged African countries to help Sudan reach a peace agreement.
On Thursday, Powell testified in the U.S. Congress that the chaos in the west of Africa's largest country amounts to genocide by the government-backed ethnic Arab militias against the region's black African Sudanese.
In a statement released by its embassy in Seoul, Sudan said Powell's conclusion was "flawed, regrettable and dismaying; it is tantamount to the blunder of weapons of mass destruction in Iraq."
Raids by government soldiers and the Janjaweed militias have killed 30,000 people and left 1.2 million homeless in 19 months. The United Nations considers it the world's worst current humanitarian crisis.
The finding of genocide was based on interviews by State Department specialists with 1,136 refugees in neighboring Chad, where they had fled from Darfur. The interviews found a "consistent and widespread pattern of atrocities committed against non-Arab villagers," a department report said.
The Sudanese embassy statement said the report was "based on partial observations by an American team that had never set foot in Darfur and interviewed politicized individual refugees in Eastern Chad."