Mr. Netanyahu arrived in New York amid street protests against him. The city’s mayor, Zohran Mamdani, had called for Mr. Netanyahu to be arrested under an International Criminal Court warrant, though he later acknowledged his own lack of power to order Mr. Netanyahu’s arrest. In his speech, Mr. Netanyahu accused Mr. Mamdani of being an “antisemite.”

His address on Thursday came hours after the Palestinian leader, Mahmoud Abbas, portrayed Israeli actions in Gaza and the West Bank as “a malicious colonial scheme” aimed at forcing Palestinians to leave their homeland. But Mr. Abbas said he still hoped for “a democratic Palestinian state that respects the rule of law and human rights.”

Mr. Abbas addressed the gathering virtually for the second year in a row because the Trump administration refused to grant him a visa. He argued in his recorded speech for a two-state solution, as he has done for decades. He was also sharply critical of Israel, saying that the state was prosecuting “a genocidal war that has created an unprecedented humanitarian catastrophe.”

Mr. Netanyahu, for his part, batted away those accusations while avoiding the topic of Gaza’s destruction. Rather than committing a genocide, he said, Israel had “prevented a genocide” against its own people by Hamas. He called claims of genocide against Israel “the greatest lie of the century.”

In September, the U.N.’s Independent International Commission of Inquiry on the Occupied Palestinian Territory issued a report saying that Israel had committed genocide in Gaza and that the perpetrators must be held accountable.

Mr. Netanyahu is also facing a tough election at home, and his political future is uncertain. His address at the U.N., analysts said, was largely directed at the audience back home and not at the international community, from which Israel is more isolated than ever.

Here’s what else to expect:

• Other notable speeches: Nepal’s prime minister, Balendra Shah, whose country suffered a devastating flood last month that was made more likely by climate change, will make his debut on the world stage later on Thursday.

• A Yemeni presence: Rashad al-Alimi, the leader of Yemen’s internationally recognized, Saudi-backed government, made an address after the truce that brought a pause in a long civil war with Iranian-backed Houthi militants unraveled recently. The Houthis have been carrying out attacks against Saudi Arabia that threaten maritime navigation in a critical Red Sea channel for global oil supplies, the Bab al-Mandab Strait. He criticized “the international community’s hesitation to designate the Houthis as a terrorist group.”

• Protesters arrested: About 100 people were arrested as people gathered in Manhattan to demonstrate against Prime Minister Benjamin Netanyahu’s appearance at the United Nations General Assembly, according to the Police Department. The arrests occurred after some protesters staged a sit-in at an intersection. Read more ›