The UN Security Council on Friday demanded aid be rushed to Gaza "at scale" as the head of the World Health Organization warned of a looming famine in the besieged Palestinian territory.
As Israeli bombs rained down on targets across Gaza, members of the UN's top peacemaking council demanded "immediate, safe and unhindered" deliveries of life-saving aid.
At Washington's insistence, the UN Security Council avoided calling for a ceasefire that would stop the 11-week-old war, which began with Hamas's bloody raids into Israel on October 7.
After the UN vote, Israel vowed to continue its air and ground assault until the Palestinian group is "eliminated" and an estimated 129 hostages still being held in the territory are freed.
"Israel will continue the war in Gaza," said Foreign Minister Eli Cohen, insisting the war was legal and just.
Israel's military said operations continued unabated in Gaza City, where its forces have been locked in street-to-street fighting with Hamas gunmen.
A spokesperson said Israel Defense Forces had destroyed an underground tunnel complex, "struck Hamas headquarters and eliminated terrorists".
Gaza's Hamas-run health ministry claimed more than 410 people had been killed in Israeli bombardments over 48 hours, including 16 in a strike Friday in the Gaza City district of Jabalia.
Four members of one family, including a girl, died in another strike on a civilian vehicle in Rafah in southern Gaza, said the ministry, which puts the death toll from the war at over 20,000.
With swathes of Gaza reduced to rubble, many Gazans have been forced into crowded shelters or tents, and are struggling to find food, fuel, water and medical supplies.
WHO boss Tedros Adhanom Ghebreyesus warned that "hunger is present, and famine is looming in Gaza".
He said a majority of displaced people were going "entire days and nights without eating".
The UN estimates that fighting has displaced almost two million Gazans, almost 80 percent of the population.
"This is not a life: no water, no food, nothing," said wheelchair-bound Walaa al-Medini, who is now in the Bureij refugee camp, in central Gaza, after a strike on her home in Gaza City.
"My daughter died in my lap, and I was rescued from under the rubble after three hours," she said. "Our house, along with everything around us, was destroyed."
Time is running out for a Christmas-time truce, despite ongoing talks brokered by Qatar, Egypt and the United States.
A one-week truce that ended on December 1 saw 105 hostages released from Gaza captivity, including 80 Israelis in exchange for 240 Palestinian prisoners.
- 'Massive obstacles' -
Friday's much-delayed UN resolution came after days of diplomatic bickering, and only passed thanks to US and Russian abstentions.
It ratchets pressure on Israel to allow greater humanitarian access and gives the United Nations a bigger role in coordinating the delivery of aid into Gaza.
"The way Israel is conducting this offensive is creating massive obstacles to the distribution of humanitarian aid," said UN chief Antonio Guterres after the vote, pressing the point home.
But it remains to be seen what, if any, impact the vote will have on the ground.
Israel's foreign minister insisted that despite the resolution his country would retain control of what goes into Gaza and "will continue to screen all humanitarian aid to Gaza for security reasons".
Hamas described the resolution as "an insufficient measure that does not respond to the catastrophic situation created by the Zionist (Israeli) war machine".
According to the UN, the number of aid trucks entering Gaza is well below the daily pre-war average.
Last week Israel approved aid delivery via Kerem Shalom crossing, and the army says on average 80 trucks enter Gaza through it daily.
Journalists in a media tour of the facility on Friday, organised by the Israeli military, could see a miles-long queue of aid trucks held up for hours as they awaited inspection by soldiers.
Egyptian driver Said Abdel Hamid seemed unfazed by the wait, saying he was "proud to bring help to my Palestinian brothers" as he removed the tarpaulin sheet covering his flour cargo for examination.
- Conflagration -
Since the conflict began, the West Bank, the Israel-Lebanese border, Iraq, Syria and the sea off Yemen have become flashpoints -- with Iranian-backed groups issuing regular warnings about their ability to take the war far beyond Gaza.
Israel said another of its troops was killed on Friday by rocket fire from Lebanon, where the Iran-backed Hezbollah and other groups have carried out near-daily cross-border assaults in support of Hamas.
Hezbollah said two of its fighters were killed Friday.
Missiles from Iran-backed Yemeni rebels -- claiming to act in solidarity with Gazans -- have disrupted Red Sea shipping.
The United States accused Tehran of being involved in the attacks. "We know that Iran was deeply involved in planning the operations against commercial vessels in the Red Sea," National Security Council spokeswoman Adrienne Watson said.
The war began on October 7 when Hamas gunmen broke through Gaza's militarised border and killed around 1,140 people in Israel, mostly civilians, according to an AFP tally based on Israeli figures.
Palestinian fighters also abducted about 250 people, 129 of whom remain in Gaza according to Israeli authorities.
Vowing to destroy Hamas, Israel launched a relentless bombardment and ground invasion of Gaza, where 20,057 people have been killed, according to the latest Hamas toll.
Most of the dead are women and children, Hamas officials say.
Body of US-Israeli hostage held in Gaza
A US-Israeli man believed to have been taken captive by Hamas militants on October 7 was killed on the day of the attack, his kibbutz community said Friday.
Palestinian fighters took the body of Gad Haggai, 73, from his community of Nir Oz in southern Israel to the Gaza Strip, the kibbutz said in a statement. His wife is believed to have been abducted alive.
The Israeli army, contacted by AFP, confirmed Haggai had died on October 7.
He is the latest confirmed fatality among about 250 Israelis and foreigners taken by Gaza militants during the deadly attack which triggered all-out war between Israel and Hamas. "Gad was murdered on October 7 at the kibbutz. His body was taken by the terrorists to the Gaza Strip and is still held there," the Nir Oz statement said.
It did not specify how Haggai's death had been confirmed.
The Hostages and Missing Persons Families Forum on Friday also announced his death without elaborating.
The slain man's wife, 70-year-old Judith Weinstein Haggai, is thought to be the oldest woman among the hostages still held in Gaza.
US President Joe Biden said in a statement he was "heartbroken by the news that American Gad Haggai is now believed to have been killed by Hamas on October 7. "We continue to pray for the well-being and safe return of his wife, Judy."
The Israeli families' forum said Gad Haggai, "a musician at heart", was a flautist who played in the military's orchestra.
The Nir Oz kibbutz said he was father of four and grandfather of seven.
Just before the abduction, his wife told a paramedic in a final phone call that they had both been wounded, their son Ahl Haggai told AFP earlier this month. "The only evidence we have... is a video of my dad on the back of a truck, lying down injured," Ahl said at the time.