RUMBEK, southern Sudan, Apr 16, 2005 -- New uniforms were issued, a military brass band had practised for days and a national holiday was declared for the Sudanese crowds who turned out yesterday to celebrate their most important guest after decades of civil war.

Robert Zoellick may only rank as the equivalent of a deputy foreign minister, but he was treated as a head of state in remote, rebel-held Rumbek.

Women ululated and barefoot children jumped up and down as the deputy secretary of state inspected the guard of honour.

The people of Rumbek in southern Sudan, mostly animists and some Christians, have been fighting for their own state. Under the north- south power-sharing accord signed with Khartoum in January, the southerners are to have a chance to vote for secession after six years.

But the Bush administration is trying to preserve Sudan's unity, fearing another fragmented, failed state and also enjoying a close counter-terrorism relationship with Sudan's Islamic government.

The international community desperately hopes that the north-south accord can serve as a political framework to resolve other conflicts across Sudan - notably Darfur in the west, where as many as 300,000 people have died in two years of fighting, disease and famine.

John Garang, the veteran leader of the rebel Sudan People's Liberation Movement, greeted Mr Zoellick for a tour of the few brick buildings remaining in Rumbek, along with scattered thatch-roofed huts and small herds of scrawny livestock.

A small oasis of comfort is provided in African Expeditions' well-appointed compound for the town's only industry - the international aid workers.

The US, under pressure from Christian lobby groups, is trying to persuade Mr Garang to share with Darfur some of the power and resources coming his way. He would be a vice-president in a national-unity government, which Mr Zoellick is pressing to be formed by July.

Several billion dollars in reconstruction aid, pledged at a donors' conference in Norway this week, could act as an incentive for all sides. Already the United Nations says some 600,000 refugees and internally displaced people have returned south; aid workers say Khartoum is evicting southerners from northern camps to make them go home.

"I want to be involved in Darfur," Mr Garang told Mr Zoellick. "You can't have peace in one part of the country and not in another."

But Mr Garang is vulnerable. Residents of Rumbek say Mr Garang's own subordinates nearly toppled him late last year, albeit probably over tribal loyalties, and there is little appetite to get involved in Darfur.

After Rumbek, Mr Zoellick flew on to Darfur, where a separate insurgency erupted two years ago as local rebels sought to fight for their slice of a possible national accord.

At El Fasher's airport surly Sudanese government troops mixed uncomfortably with local police and soldiers from the small African Union (AU) monitoring mission.

But in the nearby Abu Shouk refugee camp - one of the world's biggest, with about 100,000 residents - crowds waved to Mr Zoellick through the dust.

These fugitives from marauding Arab militia and government forces - in a conflict that the US last year denounced as genocide - are better fed by aid agencies than the people of Rumbek, but they have no freedom or security. Their safety depends on the AU mission, and the men complain that their women are raped when they venture in search of firewood.

Colin Powell, then secretary of state, visited the same camp last June. The Sudanese government assured him it would act to halt the violence, which it blamed on others.

Since then Abu Shouk has more than doubled in size. Foreign observers say government forces have been better behaved recently, but they continue to arm and train the Arab janjaweed militia, who are aggravating the conflict.

The UN, which fed some 1.4m people in Darfur last month, warns it will probably have to feed 3m by the end of the year.

Anarchy and banditry are hindering deliveries that need to be stepped up before the rainy season begins next month.