Dozens of diplomats have walked out of the UN's assembly hall as Israel's PM took to the podium to speak.
As the session's chairman called for order, there were boos and cheers while delegates streamed out, leaving masses of empty seats.
Benjamin Netanyahu used his speech to speak directly to the hostages held in Gaza and their captors.
He said loudspeakers had been put up around the territory and said Israeli spies had hacked mobile phones in the area so they carried his voice.
To the hostages he said: "We have not forgotten you... we will not falter, we will not rest until we have brought all of you home."
To Hamas's leadership, he said: "Lay down your arms... free the hostages now. If you do you will live, if you don't Israel will hunt you down."
He hit out at "false charge of genocide" and said: "If Hamas agrees to demands, war could end."
Mr Netanyahu held a map of the region and crossed out the various threats he said he been eliminated, such as Hezbollah and Iran's nuclear capabilities.
"Israel rebounded from its darkest day to deliver one of the most stunning military comebacks in history," he said.
It comes soon after the UK, France, Canada and Australia formally recognised a Palestinian state in an effort to keep alive the prospect of a two-state solution.
The war in Gaza has being going on for nearly two years, with UN agencies and its chief repeatedly warning over the dire humanitarian situation.
Israel's recently-launched ground assault on Gaza City has only heightened concerns and seen thousands flee south in fear of their lives.
Israel says it's designed to destroy what remains of Hamas after its October 2023 terror attack killed more than 1,200 people and kidnapped 251.
The Israeli leader insisted Israel had to "finish the job" to ensure the atrocity is not repeated.
"They beheaded men. They raped women. They burned babies alive. They burned babies alive in front of their parents," he told the UN.
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Mr Netanyahu previously condemned the recognition of a Palestinian state by Western powers, saying it only rewarded Hamas and made it harder to win the release of the remaining hostages.
There are fears he could retaliate by annexing the West Bank and recognising Israeli control over illegal settlements.
However, President Trump - the only world leader believed to hold any sway over Israel - told reporters yesterday that he would "not allow it".
The Israeli leader is subject to an arrest warrant from the International Criminal Court, which has accused him of crimes against humanity - which he denies.
More than 65,000 Palestinians in Gaza have been killed in the war, according to the country's Hamas-run health ministry.
Ninety per cent of its population has also been displaced by attacks that have flattened most of the territory and left many people desperately short of food.
The Israeli PM told the UN "the war could end right now" if Gaza agreed to its demands.
"Israel would retain overriding security control, and a peaceful civilian authority would be established by Gazans and others committed to peace with Israel."
He also hit out at "weak-kneed" Western leaders who he accused of giving in to biased media and antisemitic mobs.
"For much of the past two years, Israel has had to fight a seven front war against barbarism, with many of your nations opposing us," said Benjamin Netanyahu.
He denied his military was deliberately targeting civilians and referenced an assessment that it was taking more "measures to minimise civilian casualties than any military in history",
Denying genocide claims, the prime minister said the "truth had been turned on its head" and cited his forces dropping millions of leaflets and sending text messages telling people to flee prior to attacks.