The UN Security Council is to vote on a resolution put forward by the UAE calling for an "immediate humanitarian ceasefire in Gaza".
UN chief Antonio Guterres said the situation in Gaza is at breaking point and it is time to act as "the eyes of the world and the eyes of history are watching".
The US has consistently opposed international calls for a ceasefire and is thought likely to vote against the resolution.
But US Secretary of State Antony Blinken has urged Israel to do more to protect civilians, saying there is a “gap” between its promises and the reality on the ground.
Meanwhile, The Palestinian health ministry in the occupied West Bank says six Palestinians have been killed in an Israeli raid on al-Fara refugee camp.
Hamas attacked Israel in October, killing 1,200 people and taking 240 hostages, some of whom were released during a short-lived truce.
Hamas officials in Gaza say Israel has killed more than 17,177 people in its retaliatory campaign, including about 7,000 children.
Israel rejects calls for ceasefire at UN meeting
Israel's ambassador to the UN, Gilad Erdan, has firmly rejected calls for a ceasefire.
He told the UN that "a ceasefire cements Hamas’s control of Gaza" and sends a mesage that "Hamas is forgiven for their deliberate atrocities".
Erdan also said "Hamas’s oppression of Gazans" had been given a "green light by the international community".
"Without the military pressure applied on Hamas no amount of diplomacy can secure the release of hostages," he added.
Palestinian Authority says Israel will make Gaza unliveable
The Palestinian Authority's representive has spoken at the UN Security Council meeting.
Riyad Mansour said that the "Israeli's objective is clear" and that it was "to force people out".
He said Israel would "make Gaza unliveable for all" and displace people.
Mansour went on to say that he believed Israel was pushing people into the south and would eventually "launch a full-fledged attack" on the area
