Extreme hunger is intensifying in 13 global hot spots, with Gaza, Sudan, South Sudan, Haiti and Mali at immediate risk of famine without urgent humanitarian intervention, a joint United Nations report warned on Monday.The "Hunger Hotspots" report by the UN Food and Agriculture Organisation (FAO) and World Food Programme (WFP) blamed conflict, economic shocks, and climate-related hazards for conditions in the worst-hit areas.The report predicts food crises in the next five months. It called for investment and help to ensure aid delivery, which it said was being undermined by insecurity and funding gaps."This report is a red alert. We know where hunger is rising and we know who is at risk," said WFP Executive Director Cindy McCain. "Without funding and access, we cannot save lives."For famine to be declared, at least 20% of the population in an area must be suffering extreme food shortages, with 30% of children acutely malnourished and two people out of every 10,000 dying daily from starvation or malnutrition and disease.