AMNA NAWAZ: Israeli Prime Minister Benjamin Netanyahu reiterated today his determination to send troops into Rafah in Southern Gaza to rout remaining Hamas units.

The drive by Netanyahu has led to a rift with the Biden White House as it warns against an Israeli operation before more than 1.3 million Palestinians can move to safety.

And, as Nick Schifrin explains, many of those people are now starving.

NICK SCHIFRIN: In Gaza City, this is what imminent famine looks like.

Thousands of Palestinians crowd a U.N. warehouse.

The women up front, they wait for an 11-pound bag of flour like their lives depend on it, because they do.

WOMAN (through translator): People are hungry.

People will die.

They are killing people over five kilograms of flour.

My son is a martyr, and his wife died over five kilograms of flour.

YASMEEN TOTAH, Displaced Palestinian (through translator): Our suffering in Gaza is indescribable, hunger, sadness, destruction.

A bag of flour costs up to $1,000 in Gaza, $1,000.

NICK SCHIFRIN: More than half of North Gaza's population is at risk of famine; 6-year-old Fadi Alzant (ph) suffers from cystic fibrosis.

Before the war, his mother says he weighed 66 pounds.

Today, he weighs 26.

His medicine is not available, so he can't walk.

Rafah in Southern Gaza is projected to face famine by July.

Five-month-old twins Meera and Sameera are both malnourished.

WAFAA TABASI, Mother of Meera and Sameera (through translator): They should weigh 13 pounds.

They weigh 6.5 pounds.

They should be making noises, playing and laughing.

They do not make any noises or play or laugh.

NICK SCHIFRIN: In Rafah, where more than a million Gazans are now displaced, they line up with empty buckets and stomachs for the most basic of all needs, water.

The U.N. says half of Gaza's water and sanitation facilities have been damaged or destroyed.

MAHMOUD SALMAN, Displaced Palestinian (through translator): If we go back to even before the war and the catastrophe, there was a water shortage.

But, today, there's barely enough for the necessary things.

JAMES ELDER, UNICEF Spokesperson: Such severe levels of hunger, such a lack of aid coming through.

The children are starting to die of dehydration, starting to die of malnutrition.

NICK SCHIFRIN: James Elder of UNICEF is visiting Gaza this week.

We spoke to him from Rafah.

JAMES ELDER: Record number of children being killed, record number of homes destroyed, record number of civilians, of children or families falling into catastrophic food insecurity.

NICK SCHIFRIN: Today, Israeli spokesman Shimon Freedman blamed the levels of hunger in Gaza on Hamas.

SHIMON FREEDMAN, Coordination of Government Activities in the Territories: We think it's a shame that international organizations are choosing to buy into Hamas' narrative.

Hamas is trying to force a humanitarian crisis in the Gaza Strip because that's part of its strategy.

NICK SCHIFRIN: Israel says it places no restrictions on aid and that, in the past two weeks, an average of more than 200 trucks per day have entered Gaza.

Israel also coordinates with the U.S. on airdrops and facilitated the arrival and distribution of food from the first aid ship.

SHIMON FREEDMAN: While Israel went to great lengths to improve our inspection capabilities, the international organizations responsible for distributing the aid have not done the same.

Israel is inspecting the aid faster than the international organizations can distribute it.

JAMES ELDER: Outrageous how many lifesaving supplies are so desperately close to those who need them.

NICK SCHIFRIN: But Elder and the U.N. say Israel has blocked aid and the U.N.'s struggle to secure convoys is a product of Israeli constraints.

JAMES ELDER: Because of so many restrictions on aid coming in, then so many people, families, moms, children, when they see a single delivery, think, I might not see another one literally for weeks.

So, if we are able to consistently get aid in, then that sense of desperation, which can lead to insecurity, will pass.

NICK SCHIFRIN: Today, in Jerusalem, Prime Minister Benjamin Netanyahu once again said there was no way to defeat Hamas without defeating Hamas' final battalions hiding among the displaced in Rafah.

BENJAMIN NETANYAHU, Israeli Prime Minister (through translator): We are determined to complete the elimination of these battalions in Rafah, and there is no way to do it except by going in on the ground.

NICK SCHIFRIN: But, yesterday, National Security Adviser Jake Sullivan said there was another way.

JAKE SULLIVAN, U.S. National Security Adviser: Now, the president has rejected and did again today the straw man that raising questions about Rafah is the same as raising questions about defeating Hamas.

That's just nonsense.

Our position is that Hamas should not be allowed a safe haven in Rafah or anywhere else.

But a major ground operation there would be a mistake.

NICK SCHIFRIN: And so U.S. and Israeli officials will meet next week to debate the fate of a city filled with the famished.

For the "PBS NewsHour," I'm Nick Schifrin.