The United Nations Security Council should act quickly to approve sending UN peacekeepers to Darfur, the US secretary of state has said.
A UN force would have a stronger mandate than the AU peacekeepers
Condoleezza Rice was presenting a US-backed draft resolution to the Council which met following last week's peace deal for the Sudanese region.
UN troops would complement some 7,000 African Union troops already there.
Some two million people have fled their homes in what US President George W Bush describes as a "genocide".
'Enforcing the deal'
Addressing a special session of the 15-member Council, Ms Rice said the peace deal signed between the Sudanese government and western rebels in Abuja, Nigeria, provided a unique chance.
"We really have an opportunity to help end the long nightmare that has befallen the people of Darfur," she said.
It was vital to support the peace agreement and for the UN to make a strong effort to monitor and enforce the deal, Ms Rice added.
Britain's new Foreign Secretary Margaret Becket said the Abuja accord was "only the start of rebuilding Darfur".
UN Secretary General Kofi Annan said the UN would "do everything in its power to close this tragic chapter of Sudan's history".
The draft resolution calls for a better-equipped and more robust UN force than the present AU mission.
The Council adopted a statement, welcoming the Abuja agreement and urging Sudan to allow a peacekeeper assessment team to prepare for the new mission.
The statement also said a donor conference should be held without delay to support the peace process.
The Sudanese authorities on Monday reacted cautiously to a call by Mr Bush for Khartoum to end its opposition to a UN presence.
DARFUR PEACE PLAN
Pro-government Janjaweed militia to be disarmed
Rebel fighters to be incorporated into army
One-off $300m transfer to Darfur
$200m a year for the region thereafter
Compensation for those forced to flee their homes
Regional government, if approved in a vote
UN emergency relief coordinator Jan Egeland says he has received positive signals from Sudanese officials that UN troops could be deployed in Darfur.
But Mr Egeland warns it could be months before the current AU mission could be replaced by a more robust force.
Mr Egeland is visiting Darfur refugees living in border camps in neighbouring Chad on Wednesday.
On Monday, he was forced to flee the Kalma camp after violent protests.
The BBC's Jonah Fisher in Darfur's biggest refugee camp says many of the protesters said they had little faith in the new peace agreement and could only think about returning home after an international force is deployed.
On Monday, Mr Bush welcomed the peace deal between the government and the Sudan Liberation Army, aimed at ending three years of fighting in Darfur, but added that the situation remained "dire".
"We're still far away from our ultimate goal, which is the return of millions of displaced people to their homes," he said.
He announced US emergency shipments to ease the crisis in Darfur, where the World Food Programme has cut food rations in half due to a lack of funding.
The rebels took up arms in 2003, accusing the government of discriminating against the black African residents of Darfur.
Pro-government Arab Janjaweed militias then launched a retaliatory campaign but the Sudan government denies backing them.
Aid organisations say the conflict has created one of the world's worst humanitarian crises.