Israeli Prime Minister Benjamin Netanyahu spoke to world leaders at the UN General Assembly on Thursday.

He said accusations of genocide in Gaza are "the biggest lie of the century."

He also said Israel has the right to wage war against Iran.

Many delegates walked out of the hall before he began speaking.

Netanyahu said attacking Iran was one of the easiest decisions he has ever made.

He called the delegates who left "moral cowards."

He said Israel is also defending their countries.

When he took the podium, there were cheers, boos and mass walkouts.

The General Assembly president repeatedly called for order.

The Palestinian Mission to the UN had asked member nations to send as many staff as possible.

It wanted them to walk out together when Netanyahu was announced.

It said this would show that no one wants to be complicit in what it called genocide, war crimes and illegal occupation.

Israel rejects those allegations.

Netanyahu held up a pager while recalling Sept. 17, 2024.

On that day, Israel remotely detonated thousands of pagers used by Hezbollah in Lebanon.

That attack killed 12 people and wounded more than 3,000.

He also compared the Oct. 7, 2023, Hamas attack to 40,000 Americans being killed in less than 24 hours.

That attack killed about 1,200 people.

Palestinian President Mahmoud Abbas also addressed the assembly Thursday, in prerecorded remarks from Ramallah.

The United States had denied him and other top Palestinian officials visas for the second year in a row.

Abbas said Palestinians will not leave their homeland or accept displacement.

He urged the world to take real action against Israel.

The war in Gaza began on Oct. 7, 2023, when Hamas-led militants attacked Israel.

They killed around 1,200 people and kidnapped 251.

At least 73,922 Palestinians have been killed in Israel's offensive, according to the Gaza Health Ministry.

A ceasefire last October halted the heaviest fighting, but further steps have stalled.