The U.N. chief is urging Israeli forces and Gaza fighters to hold their fire, warning that a further escalation of the seven-day-old conflict would endanger the entire region.
Ban Ki-Moon says: "This must stop, immediate steps are needed to avoid further escalation, including a ground operation."
Ban's visit to Cairo comes as Egypt's new Islamist President Mohammed Morsi is trying to broker a cease-fire between the Israeli government and Gaza's Hamas rulers.
Ban met with Arab League chief Nabil Elaraby on Tuesday and will meet with Morsi before traveling to Israel later in the day. Ban says he will encourage Israeli leaders to end the violence and respect obligations under international law.