Israel plans to increase airstrikes on Gaza in preparation for the “next stages of the war,” Israel Defense Forces spokesman Rear Adm. Daniel Hagari said Saturday. His remarks, reported by the Associated Press, came the day the first aid trucks were allowed into Gaza since the war broke out. The 20 trucks — 13 carrying medical supplies, five with food and two with water — carried goods that amount to just 4 percent of Gaza’s daily imports before the recent hostilities, the United Nations said, as five U.N. aid agencies said “the world must do more.” The brief opening of Egypt’s Rafah crossing did not allow for the movement of civilians, with at least 400 U.S. citizens trapped in Gaza while Palestinians and dual nationals are unable to flee the fighting.