The United Nations is to undertake a two-day humanitarian mission to Niger on, as concern grows over an impending food crisis in the Sahel. UN Emergency Relief Coordinator Valerie Amos will lead the mission and meet with Niger's President Mahamadou Issoufu, Prime Minister Brigi Rafini and other key government officials, dpa quoted the UN as saying Wednesday. Amos would also visit the area of Tillaberi in the south-west, one of the regions likely to be hit hardest by the impending crisis. Humanitarian agencies have said that about 10 million people are likely to be affected by food insecurity once the harvest season ends. Among them are an estimated 1 million children, who risk severe malnutrition; more than three times the number of children affected in 2011.