The United Nations says $10m ($7.4m) is needed to to keep cholera from spreading in Nigeria, reports AFP news agency.
The outbreak has now killed at least 44 people in north-east Nigeria, a UN statement said.
It added that there were close to 2,300 confirmed or suspected cases.
The first cholera case was identified in Borno State on 16 August and has since spread, mainly in camps for those displaced by the Boko Haram insurgency.
Inadequate sanitation and stagnant groundwater are a cause of water-borne diseases in displaced persons camps.