"I am appalled by the reports of sexual violence," Guterres said.
UN Secretary-General Antonio Guterres said Friday that Hamas brutality could never justify "collective punishment" of Palestinians as Israel presses its campaign against Hamas in the Gaza Strip.
Guterres convened an emergency meeting of the UN Security Council after weeks of fighting left more than 17,487 people dead in Gaza, mostly women and children, according to the latest toll from the health ministry in Hamas-run Gaza.
He and a group of Arab countries are seeking a vote on an immediate ceasefire, but the veto-wielding United States said it was opposed to such a move, making it highly unlikely that such a motion would succeed.
"Some 130 hostages are still held captive. I call for their immediate and unconditional release, as well as their humane treatment and visits from the International Committee of the Red Cross until they are freed," Guterres said.
"At the same time, the brutality perpetrated by Hamas can never justify the collective punishment of the Palestinian people."
Vowing to destroy the Islamist movement, Israel has relentlessly bombarded Gaza and sent in tanks and ground troops since the war began on October 7 with unprecedented attacks by Hamas on southern Israel.
Those attacks left 1,200 people dead, Israel says.
"I unreservedly condemn those attacks. I am appalled by the reports of sexual violence," Guterres said.
"There is no possible justification for deliberately killing some 1,200 people, including 33 children, injuring thousands more, and taking hundreds of hostages."
Guterres deployed rarely-used Article 99 of the UN Charter to bring to the council's attention "any matter which in his opinion may threaten the maintenance of international peace and security".
No one in his job had done this in decades.
Guterres is seeking a "humanitarian ceasefire" to prevent "a catastrophe with potentially irreversible implications for Palestinians" and the entire Middle East.
But deputy US ambassador Robert Wood said: "While the United States strongly supports the durable peace, in which both Israelis and Palestinians can live in peace and security, we do not support calls for an immediate ceasefire."
"This would only plant the seeds for the next war," he added.
'Laws of war'
After Guterres sent his urgent letter, the United Arab Emirates prepared a draft resolution that will be put to a vote later Friday, said the delegation from Ecuador, which chairs the council this month and thus decides on scheduling issues.
The latest version of this document seen Thursday by AFP calls the humanitarian situation in Gaza "catastrophic" and "demands an immediate humanitarian ceasefire."
The short text also calls for the protection of civilians, the immediate and unconditional release of all hostages in Hamas captivity, and humanitarian access to the Gaza Strip.
Several previous attempts to pass a resolution calling for a ceasefire have been vetoed.
France's ambassador to the UN, Nicolas de Riviere, said "I don't think we can wait forever."
"But rushing to a vote without negotiating would be a big mistake.. I think 5:30 pm (2230 GMT) is too early," he said.
Washington, Israel's closest ally on the world stage, has said that a new resolution would not be "useful" at this stage.
"Today, this council will vote. It will have an opportunity to respond to the deafening calls across the world to bring this violence to an end," said the United Arab Emirates' deputy ambassador, Mohamed Issa Abushahab.
Vast areas of Gaza have been reduced to a wasteland. The United Nations says about 80 percent of the population has been displaced, facing shortages of food, fuel, water and medicine, along with the threat of disease.
"International humanitarian law includes the duty to protect civilians," Guterres said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)