UNITED NATIONS (AFP) - UN chief Ban Ki-moon on Friday renewed his call for an end to the Israeli blockade of the impoverished Gaza Strip, regretting that his earlier pleas had gone unheeded. "The secretary-general continues to express his concern at the humanitarian situation in Gaza," a statement from his office said. "He has underscored the importance of having Israel urgently permit the delivery of humanitarian assistance to the civilian population of Gaza, and regrets that his calls have not yet been heeded." Israel said Friday it would maintain its closure of the Gaza Strip despite international concern over a deterioration of the humanitarian situation in the aid-dependent Palestinian territory. "This decision was taken because of the continuation of Palestinian rocket attacks against southern Israel," said Peter Lerner, a defense ministry spokesman. The UN Relief and Works Agency, which distributes rations to half of Gaza's 1.5-million population, said it had food stocks for "days not weeks." "In the coming days we expect some food items to run out," spokesman Chris Gunness told AFP. In normal times, UNRWA distributes food to some 750,000 people, or about half the residents of the Gaza Strip.