Sudan has been promised substantial flood relief from the UN.
"Amid continued devastation caused by floods in the Sudan ... [the United Nations] has approved a grant of $8.7 million to support the ongoing humanitarian response," OCHA, the UN's humanitarian aid agency, said in a statement.
OCHA said the floods had affected hundreds of thousands of people across a dozen states in Africa's largest country and many do not have adequate access to food.
Heavy flooding in some states has destroyed lavatories and polluted water supplies, spreading deadly water-borne diseases like cholera and malaria.
A World Health Organisation (WHO) official said the number of cholera cases in east Sudan had risen to 808, including 53 deaths.
Cholera causes severe diarrhoea and can lead to death within hours if not treated.
"Eight hundred and eight cases and 53 deaths, but since the last three days there have not been any new cases," Ahmed al-Ganainy, a WHO official, said.
He added the outbreak could not be considered contained until several weeks had passed without new cases.
Sudan's Ministry of Health has been reluctant to release information on the cholera outbreak.
But the Reuters news agency obtained a ministry report last week confirming 70 per cent of the diarrhoea cases in the east of the country tested positive for cholera.
Ministry officials declined to give any information on the outbreak, but the WHO says their numbers are from the ministry.