Sudan has begun a campaign to keep African Union troops in Darfur and prevent a U.N. force from taking over efforts to restore peace in the conflict-wracked region, the top U.N. envoy in Sudan said Tuesday.

Jan Pronk said an anti-U.N. climate is heating up strongly in the Sudanese capital, Khartoum, with threats and warnings that handing over to a U.N. force would put Sudan "in the same situation as Iraq a couple of years ago."

On Jan. 12, ambassadors on the African Union's Peace and Security Council agreed in principle to hand over peacekeeping to the United Nations, but left the final decision to a ministerial meeting on Friday.

The U.N. Security Council has authorized the start of planning for a takeover and U.S. Ambassador John Bolton tried unsuccessfully to get the council to authorize the new U.N. force.

An estimated 180,000 people have died, mainly of hunger and disease, and some 2 million have been displaced since rebels from Darfur's ethnic African population revolted three years ago, accusing the Arab-dominated government in Khartoum of discrimination and decades of neglect.

The Sudanese government is widely alleged to have unleashed Arab militias who carried out sweeping atrocities against ethnic African villagers. Sudanese President Omar el-Bashir denies his government supports the militia, known as Janjaweed.

Pronk told a news conference the African Union may be reconsidering the decision to relinquish peacekeeping responsibilities. He said Friday's scheduled ministerial meeting has been postponed for a week at Sudan's request until March 10.

"Sudan has sent delegations to many countries in the world in order to plead for its case, namely, let the African Union stay and let the U.N. not come — no transition," he said. "We do not know whether the African Union next Friday will reconfirm its own decision. That is not certain any more."

If the African Union decides against handing over, he said, the Security Council cannot then say it is taking over peacekeeping.

Pronk said the situation in Darfur remains difficult with groups of 3,000 militia on camel and horseback attacking villages with army cars behind them.

Earlier this month, President Bush made his strongest statement of support yet for an expanded international role in Darfur, backing a larger force for Darfur and NATO invovlement.

Pronk said a NATO-led force in Darfur would be "a recipe for disaster."

"You need either an AU (African Union) force which is effective ....you need the U.N.," he said. "There is, in my view, no alternative." He said the present African Union force is too small.