Lise Grande, the UN humanitarian coordinator for Iraq, also said that the United Nations expects a mass exodus from Mosul - perhaps within the next few days - as Iraqi army prepares to storm the northern Iraqi city which is still home to over a million people.
In the worst case scenario, Grande said it was also possible that Islamic State fighters who have controlled Mosul for more than two years could resort to "rudimentary chemical weapons" to hold back the impending assault.