At least 1.5 million people were killed and another four million displaced, some of whom have already returned and are the priority for aid.

Khartoum will finance another 5.2 billion dollars from its own oil resources, according to a report compiled last month by government representatives and ex-rebels.

The United States was the latest country to promise financial assistance to war-wrecked Sudan.

"My country wants to improve the prospect for success in Sudan, the Comprehensive Peace Agreement (January 2005 north-south peace deal) and the resolution of conflict in Darfur," said Deputy Secretary of State Robert Zoellick.

"That is why the United States will seek to provide between one and two billion dollars for this cause during the next two years."

He said 853 million dollars would be allocated in 2005 to support the north-south reconstruction effort and humanitarian needs country-wide.

"President Bush has requested another 900 million (from congress) for this year and next," added Zoellick who will visit Sudan later this week.

But Zoellick conditioned support to rebuilding Sudan's northern and southern areas on resolving the two-year-old conflict in the country's Darfur western region that has left at least 300,000 people dead.

"If the government of Sudan and all those in Darfur fail to act against the violence to help strengthen security and create a serious peace process ... then my country and others will not be able to sustain the CPA fully," he said.

Darfur has since February 2003 been gripped by a rebellion by local people of black African origin against a government-backed Arab militia, the Janjaweed, widely accused of perpetrating genocide and a scorched earth policy against villagers.

A recent UN resolution said presumed crime criminals must be tried by the International Criminal Court in The Hague but Khartoum has squarely rejected the idea, insisting it has competent courts at home.

Among those countries making pledges on Monday, the European Union said it would contribute 756 million dollars, Britain 545 million, Norway 250 million, Italy, and Denmark 90 million for 2005-2007.

Canada also pledged Monday 73 million dollars, Germany nearly 40 million dollars and Ireland 20 million.

The World Bank, which will manage multilateral donor assistance in an effort to ensure transparency and accountability of disbursements to Sudan, promised 50 million dollars Monday.

But it was not immediately clear which proportion of the pledges was to be directed towards the 2.6 billion target.

UN Secretary General Kofi Annan urged donors Monday to make good on their pledges.

"Pledges are good but cash is better," he said, warning against "failure of donor governments to follow up on their pledges."