Battles raged across Gaza on Sunday as Israel indicated it was prepared to fight for months or longer to defeat the territory’s Hamas rulers, and a key mediator said willingness to discuss a cease-fire was fading.

Israel faces international outrage after its military offensive, with diplomatic support and arms from close ally the United States, has killed thousands of Palestinian civilians. About 90% of Gaza’s 2.3 million people have been displaced within the besieged territory, where U.N. agencies say there is no safe place to flee.

The head of the U.N. in Gaza on Sunday described the situation as the worst he’s ever seen, warning of a total humanitarian collapse inside the territory.

The United States has lent vital support in recent days by vetoing a United Nations Security Council resolution to end the fighting and pushing through an emergency sale of over $100 million worth of tank ammunition to Israel.

Russia backed the resolution. Israeli Prime Minister Benjamin Netanyahu on Sunday spoke to Russian President Vladimir Putin and expressed dissatisfaction with “anti-Israel positions” taken by Moscow’s envoys at the U.N. and elsewhere, an Israeli statement said.

Netanyahu told Putin that any country assaulted the way Israel was “would have reacted with no less force than Israel is using,” the statement added.

The U.N. General Assembly scheduled an emergency meeting Tuesday to vote on a draft resolution demanding an immediate humanitarian ceasefire in Gaza. Riyad Mansour, the Palestinian ambassador to the U.N., told The Associated Press that it’s similar to the Security Council resolution the U.S. vetoed Friday.

There are no vetoes in the General Assembly but unlike the Security Council its resolutions are not legally binding. They are important nonetheless as a barometer of global opinion.

Israel’s air and ground war has killed thousands of Palestinians, mostly civilians, since the Oct. 7 attack by Hamas and other militants killed 1,200 people and captured around 240. Over 100 of them were released during a weeklong cease-fire last month.

With very little aid allowed in, Palestinians face severe shortages of food, water and other basic goods. Some observers openly worry that Palestinians will be forced out of Gaza altogether.

“Expect public order to completely break down soon, and an even worse situation could unfold including epidemic diseases and increased pressure for mass displacement into Egypt,” U.N. Secretary-General Antonio Guterres told a forum in Qatar, a key intermediary.

Eylon Levy, an Israeli government spokesman, called allegations of mass displacement from Gaza “outrageous and false.”

Qatar’s prime minister, Sheikh Tamim bin Hamad Al Thani, told the forum that mediation efforts seeking to stop the war and have all hostages released will continue, but “unfortunately, we are not seeing the same willingness that we had seen in the weeks before.”

Israel’s national security adviser, Tzachi Hanegbi, told Israel’s Channel 12 TV that the U.S. has set no deadline for Israel to achieve its goals. “The evaluation that this can’t be measured in weeks is correct, and I’m not sure it can be measured in months,” he said.

U.S. Secretary of State Antony Blinken told CNN that as far as the duration and the conduct of the fighting, “these are decisions for Israel to make.”

This is a war that cannot be won, Jordan’s foreign minister, Ayman Safadi, asserted to the Qatar forum, warning that “Israel has created an amount of hatred that will haunt this region that will define generations to come.”

Fighting and arrests in the north

Israeli forces face heavy resistance, including in northern Gaza, where neighborhoods have been flattened by air strikes and where ground troops have operated for over six weeks.

Israel’s Channel 13 TV broadcast footage showing dozens of detainees stripped to their underwear, hands in the air. One man held an assault rifle above his head, walked forward and placed a gun on the ground.

Other videos have shown groups of unarmed men held in similar conditions, without clothes, bound and blindfolded. Detainees from a group released Saturday told The Associated Press they had been beaten and denied food and water.

Israeli military spokesperson Daniel Hagari said dozens of arrests took place in two Hamas strongholds and that people are undressed to make sure they are not hiding explosives.

Residents said there was still heavy fighting in the Gaza City neighborhood of Shijaiyah and the Jabaliya refugee camp, a dense urban area housing Palestinian families who fled or were driven out of what is now Israel during the 1948 war.

“They are attacking anything that moves,” said Hamza Abu Fatouh, a Shijaiyah resident. He said the dead and wounded were left in the streets as ambulances could not reach the area.

Israel ordered the evacuation of the northern third of the territory, including Gaza City, early in the war, but tens of thousands of people have remained.

Heavy fighting also was underway in and around the southern city of Khan Younis, which Israel claims is Hamas’ command center. Many families have been forced to flee the city and head for the border town of Rafah.

Aya Moustafa Zourab told CBS News her whole street was on fire when they left. Her child is disabled and needs medical attention. She said he is sick but there is no treatment and she has no money to travel and she has to beg others for food and water.

Waiting days for food

The price of dwindling food in Gaza has soared. Abdulsalam al-Majdalawi said he had come every day for nearly two weeks to a U.N. distribution center, hoping to get supplies for his family of seven.

“Thank God, today they drew our name,” he said.

One hundred trucks with humanitarian aid entered Sunday, said Wael Abu Omar, a spokesman for the Palestinian Crossings Authority. That’s far short of what’s needed.

A spokesperson for the U.N. in Gaza, Juliette Toumi, told CBS News it’s becoming too dangerous for aid agencies to operate.

“We have come to a point where we’re not sure if we’re able to fulfill our mandate and provide assistance to people in Gaza,” she said. “This is unprecedented.”

The World Food Program warned that half the population in Gaza faces extreme hunger and severe water restrictions. The charity group Save the Children said deaths from starvation and disease might top those killed in bombings in Gaza.

With the war in its third month, the Palestinian death toll in Gaza has surpassed 17,900, the majority women and children, according to the Health Ministry in the Hamas-controlled territory. The ministry does not differentiate between civilian and combatant deaths.

Israel holds Hamas responsible for civilian casualties, saying the militants put civilians in danger by fighting in residential neighborhoods. The military says 97 Israeli soldiers have died in the offensive. Palestinian militants have continued firing rockets into Israel.

Netanyahu’s office said Hamas still has 117 hostages and the remains of 20 people killed in captivity or during the Oct. 7 attack. The militants hope to exchange them for Palestinians imprisoned by Israel.

Israel says it has provided detailed instructions for civilians to evacuate to safer areas, even as it strikes what it says are militant targets. Thousands have fled to areas along the border with Egypt — one of the last places where aid agencies are able to deliver food and water.

Despite a series of airstrikes near the Rafah border crossing with Egypt, Israeli Col. Etad Goren told CBS News it’s safe to pass through.

“We are not attacking the humanitarian corridor,” he said. “Second, we know exactly where the shelters are We didn’t attack any truck, any U.N. truck that wanted to facilitate or to bring goods or shelter.”

Still aid agencies say tens of thousands of Palestinians will go to bed hungry and thirsty, many without shelter. 

Demonstrations were again held in several cities in support of the Palestinians and calling for an end to the war, while thousands marched in Europe against antisemitism.

The war has raised tensions across the Middle East, with Lebanon’s Hezbollah trading fire with Israel along the border and other Iran-backed militant groups targeting the U.S. in Syria and Iraq. Israeli artillery, drone, and airstrikes over Lebanon border towns intensified.