GENEVA, Sept 13 (Reuters) - U.N. Secretary-General Antonio Guterres on Monday called for donors to pledge hundreds of millions of dollars for Afghanistan, saying that poverty was spiralling and many people could run out of food by the end of the month. "After decades of war, suffering and insecurity, they face perhaps their most perilous hour," he said in opening remarks at a Geneva conference where $606 million is being sought. read more "The people of Afghanistan are facing the collapse of an entire country — all at once."