The United Nations top aid official has accused the international community of neglecting the food crisis in Niger, according to the BBC.

Some 150,000 children will die soon without aid, out of 2.5m who need food, said Jan Egeland.

"Niger is the example of a neglected emergency, where early warnings went unheeded," he told the BBC.

The UN's Niger appeal in May initially failed to attract a single pledge. But the government there has also sought to downplay the scale of the crisis.

It has refused demands to distribute free food and has been criticised for not doing more to prepare for the food shortages.

The crisis was widely predicted after last year's poor harvests, following poor rains and locust invasions.

"The world wakes up when we see images on the TV and when we see children dying," Mr Egeland told the BBC's World Today programme.

"We have received more pledges in the past week than we have in six months. But it is too late for some of these children."

The slow response has greatly increased the cost of dealing with the crisis, aid workers say.

"The funding needs are sky-rocketing because it's a matter of saving lives," said UN World Food Programme Niger representative Gian Carlo Cirri.

"The pity is we designed early enough a preventative strategy, but we didn't have the chance to implement it."

Mr Egeland said it would have cost $1 a day to prevent children becoming malnourished but it was now costing $80 a day to save a child's life.

Aid workers in Niger say that children are dying every day in feeding centres in the south of one of the world's poorest countries, much of which lies in the Sahara desert.

They say that up to a quarter of Niger's 12m people need food aid.

The UN has now received just a third of the $30m it had asked for, Mr Egeland said.

The UN under secretary general for humanitarian affairs also said that beyond immediate food aid, the world should help Niger improve its agricultural methods to avoid future food crises - but this programme had received even fewer pledges.

He said the $30m requested for both short - and long-term aid "was nothing".

"Europeans eat ice cream for $10bn a year and Americans spend $35bn on their pets each year."