The heads of all major UN agencies issued a rare joint statement on Sunday expressing outrage at the civilian death toll in Gaza and calling for an "immediate humanitarian ceasefire" in the war.
"For almost a month, the world has been watching the unfolding situation in Israel and the Occupied Palestinian Territory in shock and horror at the spiralling numbers of lives lost and torn apart," the UN chiefs said.
The heads of 18 organisations including UNICEF, the World Food Programme, and the World Health Organization laid out the toll for both sides.
In Gaza, the UN statement said, "an entire population is besieged and under attack, denied access to the essentials for survival, bombed in their homes, shelters, hospitals and places of worship. This is unacceptable."
It called on Hamas to release the more than 240 hostages it took in its surprise 7 October attack, and urged both sides to respect their obligations under international law as the war rages on.
The UN leaders said more food, water, medicine and fuel must be allowed into Gaza to help its besieged population as Israel attacks with the stated goal of destroying Hamas.
"We need an immediate humanitarian ceasefire. It's been 30 days. Enough is enough. This must stop now," the statement said.
Israeli forces have killed nearly 9,800 people in Gaza during their military campaign.
Israel has occupied Palestinian territory, including Gaza, for decades and has waged several previous assaults on the besieged enclave.
The current attack began when Hamas launched its 7 October attack, which killed more than 1,400 people.