Deputy Secretary of State Robert Zoellick is warning that increasing violence in Sudan's Darfur region could undermine a peace agreement signed earlier this year ending a 21-year civil war that killed more than two million people.

Robert Zoellick at a press conference in Khartoum

In what was billed as a major policy address delivered at the University of Khartoum, Mr. Zoellick expressed concern that the Comprehensive Peace Agreement signed last January to end Sudan's civil war could collapse under the weight of ongoing violence in Sudan's western Darfur region.

"In Sudan, when one piece of the mosaic cracks, there is a danger that everything else could fall apart," he said. "And when that happens, those who suffer most are the poor, the displaced, the dispossessed. They are the soul of Sudan, and they have already suffered far, far too much."

Since 2003, violence in Darfur has claimed the lives of at least 180,000 people and caused two million to flee their homes.

Mr. Zoellick says after a period of relative calm, an increase in bloodshed is forcing agencies like the United Nations to significantly reduce assistance to those who are most in need.

"In recent weeks we have seen a spike of violence in Darfur, with at least two separate attacks on African Union peacekeepers," said Mr. Zoellick. "Banditry against humanitarian convoys has forced the United Nations to withdraw some staff and supplies. If conditions keep deteriorating, Darfurians could suffer even more."

Mr. Zoellick met with top Sudanese officials, including President Omar al-Bashir.  He also held talks with U.N. Special Representative to Sudan Jan Pronk, who told reporters the nearly 7,000 African Union peacekeepers in Darfur are not enough to eliminate violence in an area about the size of France.

"Perhaps the possibility for the international community to come in after peace with a stronger force to keep the peace, like we have at the moment also in the south," said Mr. Pronk. "We need peace in order to solve such problems."

Thursday, Mr. Zoellick is scheduled to travel Darfur and visit two camps where tens of thousands of displaced people are living with shortages of food, medical care, and shelter.