The West African country is the 7th poorest country in the world, where more than one in five children die before the age of five.
The British aid agency Oxfam says millions of dollars are needed urgently to stop a hunger crisis in Niger turning into a catastrophe.
It says some 1.9 million people are at severe risk and that number could rise to 3.5 million next month. More than six million of the population of 17 million need immediate help.
Oxfam's Niger director Samuel Braimah said, "All signs point to an impending catastrophe" and that "the world cannot allow this to happen".
He said Oxfam has received only 2.9 million euros ($A3.69 million) of the 15 million euros it needs to help.
Oxfam blamed a lethal mix of drought, erratic rains, high food prices, entrenched poverty and regional conflict that has brought tens of thousands of refugees to Niger.
