Robert Zoellick, top deputy to Secretary of State Condoleezza Rice, traveled to Oslo, Norway, for an international conference of donors for Sudan. He was expected to announce what Bush administration officials called "a significant pledge" for Sudan and to urge similar commitments from other countries.

Sudan is seeking $2.7 billion in international aid for emergency reconstruction in southern and northern regions of the country.

Most of the money pledged will be used for reconstruction and development of the devastated southern region, where rebellion had raged since 1983. Some will be spent on humanitarian aid, while a slice will go toward implementing the peace agreement.

Since 2003, the United States has given $1 billion in aid related to the North-South war and $600 million for the western region of Darfur, mostly for humanitarian relief.

Zoellick was to meet with the Sudanese government and rebel leaders from the Sudan People's Liberation Movement while in Norway before heading to the African country later in the week. His trip is designed to encourage both sides to move more quickly on the peace deal they reached in January and then to pursue peace in Darfur.

The agreement between the ethnic Arab-dominated Sudanese government in Khartoum in the North and the black African rebels who control the South was intended to end the civil war that has claimed more than 2 million lives over two decades.

The United States says the two sides have fallen behind schedule on the agreement that lays out power- and wealth-sharing rules and says the south Sudanese will determine whether they want their region to remain part of Africa's largest country after six years.

Bush administration officials worry that the peace agreement could unravel without strong international backing, and it could be derailed if the conflict persists in Darfur.

In that region, tens of thousands of people have died and more than 2 million have been uprooted since early 2003. That's when black African farmers, claiming the government was neglecting their interests, rose up against Sudan's Arab-dominated government and government-backed Arab militias. Unlike in the North-South problem, both sides in the western Sudan fighting are Muslims.

State Department officials say while atrocities still are being committed, large-scale organized violence has lessened since January in areas where 2,200 African Union peacekeeping troops have been deployed.

The U.N. Security Council has voted to send 10,700 peacekeepers to the country to monitor the peace deal.