UNITED NATIONS — Secretary-General Ban Ki-moon criticized Israel for the death and suffering of many Palestinian children during last summer’s conflict in Gaza and urged the Israeli government to take immediate steps to prevent such killings.

The U.N. chief referred to the controversy over his decision not to include Israel on his annual list of parties that kill or injure children in armed conflict. Nonetheless, he singled out Israel’s actions in a speech Thursday to a Security Council meeting on children and armed conflict.

Ban expressed deep alarm at the Gaza killings and urged Israel to review its policies and protect the lives of Palestinian children, who have borne the brunt of its military operations in Gaza.

“Last year was one of the worst in recent memory for children in countries affected by conflict,” the U.N. leader said, adding he is “deeply alarmed at the suffering of so many children as a result of Israeli military operations in Gaza last year.”

More than 500 children died during the conflict in Gaza last year. A U.N. report accused the Israeli army of being responsible for strikes on buildings where civilians were sheltering during the conflict.