Israel-Gaza live updates: 3 premature babies die at Al-Shifa Hospital, doctor says

National Security Council spokesman John Kirby said there are about 500 to 600 Americans and family members remaining in Gaza.

Asked if the lack of humanitarian pauses is a factor in why hundreds of Americans remain in Gaza, Kirby said it’s among the many "complicating factors."

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IDF forces fighting in Gaza City

ABC News’ Ines de la Cuetara is in Israel and has the details on Israel Defense Forces fighting in the heart of Gaza trying to root out Hamas.

Kirby would not confirm Axios' report that President Joe Biden is asking Israeli Prime Minister Benjamin Netanyahu for a three-day pause to allow progress in releasing more hostages, but Kirby said that discussions are ongoing with Israel, noting that there have been pauses in the past.

Kirby said they are trying to get an agreement "for as many pauses as might be necessary to get all of them out," but called it a "delicate negotiating process," and laid out some of the options that are being floated.

"What we're talking about here is temporary, fixed in time, short duration, hours to days, depends on the need. And then also localized in terms of the map," he explained. "So it would be an agreement that for a set period of time [in a set area] there will be a pause in the fighting. That doesn't mean that there won't be or couldn't be fighting outside that zone during that same period of time. So all of that has to get factored in and I have no doubt that on the Israeli side, as they look at each proposal, they'll think about the impact, potential impact, on their military operations on the ground or in the air."

-ABC News' Justin Ryan Gomez

Over one month since Hamas took more than 200 people hostage in Israel, National Security Council spokesman John Kirby said the administration is still "not aware of any specific proof of life."

"We don't have any indication to the contrary, that they aren't still alive. And so, we're certainly operating under that assumption," he said.

"We don't have a perfect picture about where everybody is, what condition they're in, or how they're being held," Kirby continued. "We cannot rule out the possibility that other groups than Hamas may have hostages that they're holding."

-ABC News' Justin Ryan Gomez

United Nations High Commissioner for Human Rights Volker Turk said both Hamas and Israel have committed war crimes since Oct. 7.

"The atrocities perpetrated by Palestinian armed groups on 7 October were heinous, they were war crimes -- as is the continued holding of hostages," Turk said.

"The collective punishment by Israel of Palestinian civilians is also a war crime, as is unlawful forcible evacuation of civilians," he added.

United Nations Secretary-General Antonio Guterres told the Reuters NEXT conference that there's something "clearly wrong" with the Israeli military's operations when looking at the number of civilians killed in Gaza.

"There are violations by Hamas when they have human shields. But when one looks at the number of civilians that were killed with the [Israeli] military operations, there is something that is clearly wrong," Guterres said.

More than 4,000 children have died in Gaza since Oct. 7, according to the Hamas-run Gaza Health Ministry.

Guterres added that it hurts the world's public opinion of Israel "to see every day the terrible image of the dramatic humanitarian needs of the Palestinian people."