UN Secretary-General Ban Ki-moon, who belives that the food crisis had reached emergency proportions, is considering to convene a world summit to discuss how to respond to the crisis, his spokesperson said Thursday. "Yes, that is exactly what he is considering," spokesperson Michele Montas said when asked whether the UN chief plans to hold a gathering of world leaders to find ways to respond to the grave problems of food availability and high prices that have led to protests and tensions in many countries.