In the south, reconstruction, development and security initiatives have yet to get off the ground more than 14 months after a peace agreement ending two decades of civil war there, while in a separate conflict in Darfur, a ceasefire is being completely ignored and killing continues, Pronk said.

Sudan's government reached a peace deal with southern rebels in January 2005, and the Security Council approved a peacekeeping mission for the south two months later. It has been slowly deploying ever since and is now up to 80% of full strength, said Pronk.

But former rebel units have yet to be disbanded, weapons remain in abundant supply, and violent clashes between rival armed groups are on the rise as a result, he said.

Yet peacekeepers cannot step in because the security mechanism envisioned by the peace deal has not begun functioning and the government has imposed restrictions on UN troop movements in the affected areas, he said.

If the south's problems are not addressed, "people will ask what difference peace has made for them. Frustration will mount. Violence will increase," Pronk predicted.

Strengthening of peacekeeping forces needed

In Darfur, fighting still rages between government and rebel forces despite a ceasefire and the government is still supporting Arab militias conducting ethnic cleansing in "village after village," said Pronk.

To quell the violence in Darfur, he called on the international community to quickly beef up an African Union (AU) peacekeeping force of some 7 000 troops already there, and not wait until that force is reconfigured as a UN force in a move expected later this year.

"Whoever is on the ground and whenever the transition will take place, a substantial strengthening of the present peacekeeping forces in Darfur is required as soon as possible," Pronk said.

The AU's Peace and Security Council voted this month to extend its mission through Septenmber 30 but affirmed in principle its plan to eventually hand off to a UN force.

Sudan's government, however, has said it does not want UN troops in Darfur until a peace deal is reached in talks taking place in the Nigerian capital Abuja.