The UN Security Council could act if violence continued in the region where about one million people have fled their homes, he said in Khartoum.

UN secretary general Kofi Annan is also in Sudan to discuss Darfur.

The Sudanese government has promised fresh action to address the conflict.

Foreign Minister Mustafa Ismail said at a joint news conference with Mr Powell that Sudan accepted there was a "problem" in Darfur but suggested it had been exaggerated.

"We believe that there is no famine, no epidemic, but that does not mean that there is no humanitarian problem which needs to be taken care of," he said on Tuesday.

He said that the government would unveil a new set of measures before the end of the visit of Mr Powell, the highest-ranking US official to travel to Sudan in two decades.

Mr Powell went into talks with Sudanese President Omar al-Bashir after his arrival on Tuesday, equipped with satellite photographs of empty, ruined villages in Darfur.

"Unless we see more moves soon in all these areas, it may be necessary for the international community to begin considering other actions, to include Security Council action," Mr Powell said.

Earlier, he said the death rate seemed set to "go up significantly" in Darfur.

"We see indicators and elements that would start to move you toward a genocidal conclusion but we're not there yet," he said en route to Khartoum from Turkey.

"We can find the right label for it later, we have got to deal with it now."

Mr Annan has also warned the UN Security Council may act if Sudan fails to tackle the crisis which developed after two rebel groups took up arms against the government in February of last year, demanding more rights for black Africans.