The conflict in Sudan's western Darfur region has worsened, with 200,000 additional people being forced from their homes, a top U.N. envoy barred from visiting the zone by Sudanese authorities said Tuesday.

Jan Egeland, U.N. under-secretary-general for Humanitarian Affairs and Emergency Relief, said Sudanese government officials had denied his U.N. aircraft permission to overfly Darfur in order to visit Sudanese refugees in neighboring Chad. A day earlier, they had barred him from visiting the capital, Khartoum, and the Darfur region.

"Many believe the problems are over in Darfur. They are getting worse," he told journalists in Kenya after leaving southern Sudan.

At least 200,000 people have been forced to flee their homes in the last four months because of the violence, he said.

Fighting in Darfur has left about 180,000 dead — most from disease and hunger — and displaced another 2 million from their homes. Egeland has called the situation in Darfur — and in the refugee camps in neighboring Chad — the worst humanitarian crisis in the world at the moment.

Egeland had been scheduled to visit Darfur to assess relief operations. Instead, he went to southern Sudan for the second leg of his mission, to check on progress toward implementing a peace accord between the Sudanese government and the semiautonomous former rebel movement.

The 3-year-old conflict in Darfur set the Arab-dominated government and militias, known as Janjaweed, against ethnic African tribes. Sudan's government and rebels in Darfur have made little headway in peace talks in Abuja, Nigeria.

"I believe that there is now a total lack of unity of command. The government doesn't control the Janjaweed militias — perhaps not even their own soldiers. The guerrillas are not controlling their armed troops on the ground," Egeland said.

Government and rebel representatives at peace talks in Nigeria "are procrastinating, the people in the field are looting and pillaging even aid work," he said.

U.N. Secretary-General Kofi Annan expressed "regret" Tuesday at the government's decision to bar Egeland from visiting Darfur and will try to speak to Sudanese President Omar al-Bashir about it, U.N. spokesman Stephane Dujarric said at U.N. headquarters in New York.

"The pressing and urgent humanitarian requirements of Darfur are a priority for the United Nations and coordination efforts to sustain this large program were at the center of Mr. Egeland's visit," Dujarric said.

The U.N. Security Council was briefed on Egeland's problems with Sudan Tuesday, Dujarric said.

Egeland said Sudanese authorities told him that visiting Khartoum and Darfur, in the Muslim part of the country, would be too sensitive because his nation, Norway, was among those that published offensive cartoons of Islam's Prophet Muhammad.

He called the excuse "utterly ridiculous."

Egeland said that in addition to denying him permission to visit Darfur, the Sudanese government has also ordered the Norwegian Refugee Council to leave the country by Wednesday. He said Khartoum did not explain the order to expel the aid agency, which is responsible for operating one of the largest humanitarian operations in Darfur.

Sudanese government officials were not immediately available for comment.

"As we speak, we have already lost contact with 300,000 people — 300,000 of the 3 million people who need our assistance we cannot reach because of insecurity or because of other obstacles to our work," Egeland said.

The international community must also pay more attention to Darfur, for which there has been "waning interest," he added.

The international community has to put pressure not only on the government of Sudan, but also on the rebel groups who "have behaved in a totally irresponsible manner."

Egeland also said the African Union peacekeeping force in Darfur was ill-equipped to protect civilians from atrocities committed by both sides of the conflict. He called for a stronger force, echoing calls for a U.N.-led force to take over the peacekeeping mission.

"World leaders thought it was going well in Darfur. It was not, and we did not keep pressure on the government nor on the guerillas," he said.