By Laura MacInnis

GENEVA, Nov 20 (AlertNet) - Any decrease in humanitarian aid due to the global credit crunch could put millions of lives in Sudan's violent Darfur region at risk, a top United Nations official has warned.

U.N. Emergency Relief Coordinator John Holmes said on Thursday the conflict in the west of the country has driven 2.7 million people from their homes. Fighting broke out in 2003 when rebels took up arms against the Sudanese government, and after six years of fighting, media attention has waned.

"Leaving Darfur in its present state is not an acceptable option for anyone," Holmes said in a pitch to donor governments for $2.2 billion in aid for Sudan next year. Just under half of that - some $1.05 billion - is for Darfur.

The allocation for Sudan is the largest amount the United Nations is seeking for any single country in its record $7 billion global appeal for 2009. Sudan also dominated the U.N.'s humanitarian work in 2008.

About 4.5 million of Darfur's 6 million people depend on international assistance to survive, and flare-ups in violence have made it extremely difficult to access schools, clinics, agricultural land and displacement camps, Holmes said.

He acknowledged that the size of the appeal was ambitious given the tough global economic environment - which has strained the budgets of traditional donor governments such as the United States, France and Britain - and growing needs in other African countries, including Democratic Republic of Congo and Somalia.

"But now is not the time to slacken or reduce our efforts in Sudan," he said. "More than ever, the international community and the governments concerned need to pull together to ensure that millions of people are afforded access to relief and recovery assistance. Otherwise we risk undermining achievements to date or jeopardising critical events ahead."

About 2 million refugees have gone back to Sudan since a peace deal was signed to resolve a separate conflict in the country's south in 2005. But Holmes said "double that number" have not yet been able to return, stressing the lack of water, sanitation and other basic services in many parts of the country.

"Conditions in south Sudan remain dire for far too many people," he said, noting that a higher percentage of women die in child birth and fewer children are fully immunised than almost anywhere else in the world.

Holmes said that in the first six months of this year, more than 600,000 Sudanese households had received food aid, half a million had been given livelihood support, more than nine million children were vaccinated against polio, and more than 2.8 million people were provided with safe drinking water.