Drought and locust invasions have wiped out crops in Niger, one of the world's poorest countries also facing an outbreak of deadly diseases including cholera.

President Jacques Chirac said on Saturday France would also double its contributions to the World Food Programme, of which one million euros would be used to supply school canteens in the most affected regions.

"This catastrophic situation highlights Niger's dependence on climatic conditions and water resources," Chirac wrote in a letter to Niger's President Mamadou Tandja released on Saturday.

France's Foreign Minister Philippe Douste-Blazy arrived in Niger on Saturday to oversee the aids delivery and determine what more was needed.

Emergency donations to Niger have increased in response to harrowing images of emaciated infants, kick-starting operations after nine months of appeals by the government for help.

Poverty and hunger kill one in four children under the age of five in Niger, a mainly desert country on the southern fringe of the Sahara.