Prime Minister Benjamin Netanyahu, addressing world leaders on Thursday in a defiant oration, dismissed allegations of Israeli genocide in Gaza as not merely false but “the biggest lie of the century,” simultaneously asserting his nation’s prerogative to wage war against Iran — a speech that went unheard by scores of delegates who had trooped out before he commenced speaking.

Netanyahu, his voice swelling with emphasis, declared that attacking Iran “was one of the easiest decisions I’ve ever had to make,” and denounced as “moral cowards” a mass of delegates who walked out of the U.N. General Assembly when he took the podium to speak.

"In defending itself, Israel is likewise defending many of the nations whose delegates have but moments ago vacated this chamber," Netanyahu said.

"Indeed, I would have you know that not a few of their leaders privately express their gratitude to us for having eliminated Iran's nuclear capabilities."

When Netanyahu ascended to the rostrum, a confluence of approbation, disapprobation, and wholesale walkouts erupted.

Scores of delegates absconded en masse, leaving a preponderance of visible seats conspicuously vacant thereafter.

“Order in the hall, please,” General Assembly President Khalilur Rahman reiterated.

"If any further moral cowards remain in this hall, I would ask that they now take their leave," Netanyahu said.

His remarks — which at times evinced the cadence of a stump speech as Israel braces for elections — followed a week replete with addresses by world leaders levelling accusations of genocide and war crimes against Israel in Gaza.

The Palestinian Mission to the U.N. conveyed, via a message dispatched to many of the 193 U.N. member nations, an exhortation to bring as many staff as possible to the assembly hall and “collectively walk out of the assembly” once the Israeli prime minister is announced.

“This will dispatch an unequivocal message unto Netanyahu and his government that no one is willing to aid, abet, or be complicit in its genocide and war crimes and illegal occupation, which all peace-loving states and peoples demand must be brought to an end,” the message said.

Israel repudiates allegations that it perpetrated genocide and war crimes and is unlawfully occupying Palestinian territory.

All Israeli settlements are illicit under international law, yet the Israeli government maintains that they are lawful.

Netanyahu, whose General Assembly addresses are wont to be punctuated by visual aids, at one juncture brandished a pager, invoking for his audience the date of Sept. 17, 2024, when Israel remotely detonated thousands of such devices that had been disseminated among the Iran-backed Hezbollah militant group in Lebanon.

The pager attack left more than 3,000 people wounded and 12 dead, among them two children.

He apprised the assembly of the magnitude of the Oct. 7, 2023, attack, in which Hamas militants slew approximately 1,200 people.

“This is tantamount to 40,000 innocent Americans slaughtered in under 24 hours,” he said, or 16 times the death toll of the 9/11 attacks, which left nearly 3,000 people dead in New York.

Netanyahu conveyed his gratitude to U.S. President Donald Trump for having taken decisive action against Iran, and he maintained unequivocally that Israel would prevail: “We will continue to win because we have no other choice.”

Mahmoud Abbas, the Palestinian President, likewise addressed the U.N. General Assembly earlier on Thursday, delivering prerecorded remarks from his office in Ramallah, this after the United States denied him and other senior Palestinian officials visas to attend the gathering for a second consecutive year.

The 90-year-old leader’s popularity at home and relevance abroad have both waned.

Yet in his remarks, Abbas made abundantly clear that he had no intention of quietly acquiescing to being sidelined.

"We shall not forsake our homeland.

We shall not acquiesce to displacement.

And we shall not permit anyone to determine our future on our behalf," Abbas said.

Notwithstanding that world leaders had, throughout the week, repeatedly invoked the plight of the Palestinians in their speeches, Abbas exhorted the international community to undertake more tangible action against Israel.

“How long will certain nations persist in their silence regarding Israel, or in furnishing it with weaponry that it deploys against our people?

The world has borne witness to the exorbitant toll exacted upon the Gaza Strip and the West Bank,” Abbas said.

“What, then, does the international community await before it intervenes to safeguard the Palestinian people?”

In years past, Netanyahu has availed himself of his General Assembly address both to excoriate the United Nations as biased and to plead Israel’s cause before world leaders.

His speech — slated for prime time in Israel — constitutes the centrepiece of a curtailed sojourn to the United States unfolding beneath the shadow of New York City Mayor Zohran Mamdani branding him a “war criminal” and agitating for his arrest.

Mamdani has conceded that New York lacks the requisite authority to execute an International Criminal Court warrant, yet he exhorted federal authorities to do so.

Israel has found itself progressively more isolated over the course of the war in Gaza.

That war was precipitated on Oct. 7, 2023, when militants under Hamas's leadership mounted an assault on Israel, killing approximately 1,200 people and abducting 251.

At least 73,922 Palestinians have been killed in Israel's ensuing offensive, according to the Gaza Health Ministry, an arm of the Hamas-run government whose figures are broadly regarded as credible by the international community.

A ceasefire to which Israel and Hamas acceded last October arrested the most intense phase of the fighting and secured the release of the remaining hostages, yet subsequent strides have since foundered.

Israel retains dominion over the greater part of Gaza and persists in conducting airstrikes against Palestinians in proximity to militarily held zones.

Hamas has neither disarmed nor ceded power, and no headway whatsoever has been made toward reconstruction of the largely devastated territory.

Netanyahu has averred that no Palestinian state shall be established for as long as he remains at Israel's helm, and has contended that the Palestinian Authority constitutes no partner for peace.

Netanyahu dismissed incidents of Israeli settler violence against Palestinians in the West Bank as a “handful of young juvenile delinquents” hurling stones, felling olive trees and setting fires.

“I cannot abide that. I will not countenance vigilantism,” the prime minister said before accusing foreign leaders and the international press of distorting the scale of violence in the West Bank.

Netanyahu’s government is in thrall to settlers and their confederates, not least the Cabinet minister vested with oversight of the police.

Arrests of settlers implicated in attacks upon Palestinians have been conspicuously scarce.

Israel seized the West Bank and east Jerusalem during the 1967 war, both of which the Palestinians envisage as integral to their prospective state.

The settlements are regarded by the Palestinians and a substantial segment of the international community as illegal and as constituting an impediment to the establishment of a viable, contiguous Palestinian state.

Reporters Jennifer Peltz and Edith M. Lederer contributed to this report.