U.S. Deputy Secretary of State Robert Zoellick has wrapped up his trip to Sudan, with a visit to the southern capital of Juba, where he urged officials to help end the war in the country's Darfur region and implement a new peace agreement with Khartoum.

Mr. Zoellick came to the southern Sudanese capital to announce the opening of a U.S. consulate here to help coordinate the hundreds of millions of dollars in development money expected to pour into this impoverished region in the coming years.

The huge improvement effort in one of Africa's poorest regions comes after a peace agreement between the mostly Arab Muslim north and the animist and Christian south signed earlier this year to end a lengthy civil war.

Mr. Zoellick says the area is just beginning to emerge from the devastation of the war, which killed two million people.

"This is an area that still bears the scars of 21 years of a very fierce civil war,"  he said. "But now there is a chance for peace. I was struck as I was driving over to see the school children in uniforms and starting to see the construction."

The new north-south Government of National Unity is urging the Bush administration to drop sanctions against Sudan imposed in 1997, saying the penalties are hurting efforts to improve the country's economy.

Mr. Zoellick says, however, the sanctions will remain in place, especially because of the continuing violence between rebels and pro-government militias in Sudan's western Darfur region.

"The sanctions were really applied for three difference reasons," he said. "One is the north-south struggle. The second is terrorism and the third is Darfur. So I have been very clear to all parties that we have to resolve each of those problems to remove the sanctions."

Mr. Zoellick held talks in Juba with Sudanese First Vice President Salva Kiir Mayardit. Mr. Kiir revealed that he has held talks this week with rebel factions in Darfur, urging them to unite and negotiate their own peace agreement with the government.

Mr. Kiir says the experience of his own rebel army, the Sudan People's Liberation Movement, makes it clear the Darfur rebels need to unite before they can effectively negotiate peace.

"Given our experience, when we broke up into many, many factions it delayed the peace process and it really dislocated us and we did not have effective military advantages until we reunited and we became strong," said Salva Kiir Mayardit.

Mr. Zoellick told reporters that Assistant Secretary of State for African Affairs, Jendayi Frazier, has met privately with the newly elected president of the Darfur rebels, Mani Arkko Minawi. Mr. Zoellick says Mr. Minawi has agreed to attend the next round of peace talks on Darfur later this month.