UN Secretary General Antonio Guterres warned on Monday that Gaza is becoming a "graveyard for children", calling for an urgent ceasefire in the enclave.

"Ground operations by the Israel Defence Forces and continued bombardment are hitting civilians, hospitals, refugee camps, mosques, churches and UN facilities – including shelters. No one is safe," Guterres told reporters.

"At the same time, Hamas and other militants use civilians as human shields and continue to launch rockets indiscriminately towards Israel," he said.

The UN Security Council met behind closed-doors on Monday. The 15-member body is still trying to agree a resolution after failing four times in two weeks to take action. Diplomats said a key obstacle is whether to call for a ceasefire, cessation of hostilities or humanitarian pauses to allow aid access in Gaza.

When asked if there were any talks at the United Nations yet about what might happen in Gaza once the fighting stops, Deputy US Ambassador to the UN Robert Wood told reporters on Monday: "Obviously there is concern about what happens the day after, but we're not at that point."

Prime Minister Benjamin Netanyahu said Israel would consider "tactical little pauses" in Gaza fighting to facilitate the entry of aid or the exit of hostages, but again rejected calls for a general ceasefire despite growing international pressure.

Speaking in a US television interview, Netanyahu, whose country has vowed to destroy Gaza's Hamas rulers, said he thought Israel would need security responsibility over the Palestinian enclave for an "indefinite period" after the war.

Asked about the potential for humanitarian pauses in fighting, Netanyahu said a general ceasefire would hamper his country's war effort.

"As far as tactical little pauses - an hour here, an hour there - we've had them before. I suppose we'll check the circumstances in order to enable goods, humanitarian goods to come in, or our hostages, individual hostages, to leave," Netanyahu told ABC News on Monday.

"But I don't think there's going to be a general ceasefire."

Both Israel and the Hamas militants who control Gaza have rebuffed mounting international pressure for a ceasefire. Israel says hostages taken by Hamas in southern Israel on October 7 should be released first. Hamas says it will not free them nor stop fighting while Gaza is under assault. (Reuters)