Condoleezza Rice, US secretary of state, had said on Thursday that genocide was continuing in Darfur through a widespread campaign of rape, looting and killing and urged the African Union (AU) to accept the help of UN peacekeepers to stop the atrocities.
Jamal Ibrahim, a Sudanese foreign ministry spokesman, said: "She is biased because any authentic parties who are concerned with what's going on in Darfur have confirmed that this is not genocide.
"This is a systematic policy of the US administration ... of pressuring the Khartoum government," he said, accusing the US of responding to internal pressures from Congress and the African American lobby.
Lam Akol, the foreign minister, said he had not heard Rice's comments, but told Reuters: "Of course there is no genocide in Darfur."
George Bush, the US president, said on Friday that double the number of peacekeepers than the already 7000-strong African Union monitors and troops deployed there were needed to stop the violence, which has so far killed tens of thousands. He said a Nato organisational role would be needed.
Sudan has previously refused to accept any foreign troops in Darfur, preferring only African soldiers.
Condoleezza Rice (L) has accused
Sudan of genocide in Darfur
But Khartoum has shown signs of softening its position towards a transition from the AU force to a UN force. The AU's Peace and Security Council will take a final decision in early March; but the council said "in principle" it supported it.
Ibrahim said on Saturday the government had not yet decided to accept or reject a transition to a UN force or any other in Darfur.
The United Nations has already begun contingency planning for such a move which could take nine months to a year to complete. Additional funds have been requested to support the AU force till then. The AU relies on donor nations to fund its mission.
The UN is deploying more than 10,000 peacekeepers to Sudan's south where a separate and bloodier civil war - Africa's longest - ended with a peace deal last year.
"We still feel it is early to accept or not to accept. It is still under discussion," he said. "It is not acceptable for any party to make a unilateral assessment of the role of the AU forces in Darfur."
The AU has been accused of standing by and watching when civilians have been attacked and have themselves become a target of ambushes and kidnappings in the vast region.
They have had limited success in halting attacks on the more than two million Darfuris living in camps after fleeing attacks on their villages.
But the African body, which built its force up from a mere 300 at the start of its deployment 18 months ago to its present strength of about 7000, says it has suffered from unreliable sources of funds and a lack of equipment.
The AU is accused of not
stopping attacks on civilians
An AU soldier shot and wounded his officer this month in a dispute over the late payment of salaries.
All these reasons led Kofi Annan, the UN secretary-general, to describe as "inevitable" a transition from the AU force to a UN peacekeeping force. The International Criminal Court (ICC) is investigating alleged war crimes in Darfur.
A UN-supported inquiry concluded that senior government and military officials, militia leaders and some rebel commanders were responsible for war crimes. It gave its documents to the ICC last year, including a sealed list of 51 suspects.