UNICEF's Executive Director Anthony Lake has called for an urgent escalation of humanitarian efforts to stop the crisis in West Africa.
Malnutrition in the Sahel region of West Africa has reached emergency levels, with at least one million children at risk of dying within months.
"There is growing insecurity here," Lake said during a visit to western Chad. "Hundreds of thousands of people have been displaced, and food prices are rising after a bad harvest."
He added: "As a result, children are now finding it harder to bounce back and resist other health threats like polio, measles, meningitis, and cholera. It's a perfect storm with one million children at risk."
How UNICEF is helping
UNICEF has set up hundreds of feeding centres across all eight countries of the Sahel. Around 15 million people have been affected by drought and rising food prices.
During January and February tens of thousands of children were treated for severe acute malnutrition, and feeding centres are filling up fast.
The alarm bell was sounded in December 2011, but responses to the Sahel crisis simply aren't meeting needs.
This week UNICEF UK and its colleagues around the world launched an unprecedented mass social media campaign, based around the hashtag #SahelNOW, to raise awareness about the plight of children in the Sahel and to raise urgently needed funds.
"This is not just about saving lives today," Lake said. "It’s about preventing new emergencies tomorrow with and boosting robust health systems so that we can prevent another tragic emergency."