Israel-Gaza updates: US ambassador to Israel demands return of hostages

The U.S. ambassador to Israel, Jack Lew, addressed a rally in Tel Aviv on Sunday demanding the immediate return of the hostages still being held by Hamas.

"One day is too many -- 100 days is unfathomable," Lew told the crowd. "My heart aches for all who have been affected by Oct. 7 and I stand in solidarity, as does the United States, with the families of the hostages. I add my voice to theirs to say: Bring them home now."

Tens of thousands of Israelis have rallied over the last 24 hours to demand the return of the hostages on the 100th day of their captivity.

-ABC News’ Patrick Reevell

Israel will pursue its war against Hamas until victory and will not be stopped by anyone, including the world court, Prime Minister Benjamin Netanyahu said in a defiant speech Saturday evening.

Netanyahu spoke after the International Court of Justice at The Hague held two days of hearings on South Africa's allegations that Israel is committing genocide against Palestinians, a charge Israel has rejected as libelous and hypocritical.

South Africa asked the court to order Israel to halt its blistering air and ground offensive in an interim step.

"No one will stop us, not The Hague, not the axis of evil and not anyone else," Netanyahu said in televised remarks, referring to Iran and its allied militias.

The case before the world court is expected to go on for years, but a ruling on interim steps could come within weeks. Court rulings are binding but difficult to enforce.

Netanyahu made clear that Israel would ignore orders to halt the fighting, potentially deepening its isolation. Netanyahu also said a decision had yet to be made about a potential military takeover of the "Philadelphi Corridor" along the Gaza Strip's border with Egypt.

-ABC News' Bruno Nota

As Sunday dawns in the Middle East, it will mark 100 days since the Israel-Hamas war began, the deadliest conflict between the two sides in recent history.

The fighting began on Oct. 7 when Hamas launched a surprise attack in southern Israel. Since then, Israel has launched numerous airstrikes and a ground offensive. The Israeli government has previously claimed it is defending itself.

More than 23,300 people have been killed in Gaza since the war began, according to the Hamas-run Gaza Health Ministry. Meanwhile, 1,200 people have been killed in Israel along with 520 Israel Defense Forces officers since Oct. 7.

Philippe Lazzarini, head of the U.N's Palestinian Relief Agency, issued a statement marking 100 days of the war, saying there are now 1.4 million people in U.N. shelters in Gaza and facing a “looming famine.”

Meanwhile, families of the Israeli hostages still held in Gaza are holding a series of events to mark 100 days since their captivity began.

-ABC News' Mary Kekatos and Patrick Reevell

About 577,000 people in Gaza, equal to a quarter of the population, are now starving, Arif Husain, chief economist for the U.N.'s World Food program, told ABC News.

Hussain has worked as an expert assessing hunger crises for 20 years and said, in terms of scale of severity and speed, he has never seen what is unfolding in Gaza right now, calling it “unprecedented.”

Even before the war with Israel, Gaza relied on humanitarian assistance to meet around 75% to 80% of its needs. With Israel now allowing very few supplies into Gaza, it has quickly run into massive shortages.

“If things continue as they are, or if things worsen, we are looking at a full fledged famine within the next six months," he said.

-ABC News' Patrick Reevell