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."

The Rafah border crossing between Egypt and Gaza was closed Wednesday due to a "security circumstance," Deputy State Department spokesperson Vedant Patel said.

Patel said he could not give any details on the security situation.

"We're continuing to work with, in partnership with, the government of Egypt and the government of Israel toward safe passage for more U.S. citizens, eligible family members and lawful permanent resident,” he added.

-ABC News' Shannon Crawford

Hamas is ready to release civilian hostages if "suitable conditions are facilitated," a Hamas spokesperson said in a press conference Wednesday.

"From the beginning we have announced our position very clearly," said Hamas spokesman Bassem Naim at a press conference in Beirut, Lebanon. "We are ready to release all the civilians and foreigners inside the Gaza Strip, if the suitable conditions are facilitated, mainly by the Israelis ... in accepting an immediate cease-fire along the whole Gaza Strip."

Israeli media is reporting that Israel is in advanced talks to come to an agreement on releasing a group of hostages in exchange for a humanitarian pause. Israel wants a much larger group of hostages released than the 10 to 15 being proposed. Qatar and Egypt are leading the negotiations.

State Department deputy spokesperson Vedant Patel declined to confirm or deny the reports on potential hostage negotiations.

"We've seen those reports" but won't "get into the specifics of any of our negotiations or discussions," he said. "I will just reiterate that we have been working around the clock to determine the whereabouts of these hostages. We're working with the Israeli government on every aspect of this including sharing intelligence experts, offering our insight."

Patel did, however, pour some cold water on the notion that Hamas was ready to release hostages or that Israel was refusing a reasonable deal to free them, dismissing recent statements from the group’s military leaders.

"The proof should be in the actions that they undertake, and so if they have a desire to release hostages, we would welcome that," he said.

The Israel Defense Forces said its soldiers have destroyed 130 Hamas tunnel shafts in northern Gaza since Oct. 7.

A mother of four in Gaza told ABC News she is worried about getting vaccinations for her days-old newborn and keeping her children warm and fed.

"I'm afraid for him because there is no warmth, no vaccinations, and no good health supplies," Maha al Sharbsy, 32, said of her fourth child, Mohammed, who was born on Saturday. "The child has started to show signs of jaundice, and his condition is unstable."

Al Sharbsy said she and her children evacuated northern Gaza days after the war started following "intense" bombings. Now in southern Gaza, she said her children cannot sleep "because there are no winter clothes and no food," and she doesn't have money to buy food.

"I want the children to live in peace, cleanliness, and good health conditions. At the very least, for the sake of the children," she said. "We, the adults, are not the issue; the children are what matter."

Her 9-year-old son, Riad, told ABC News he misses his room and toys and is worried for his family.

"I'm afraid of the rockets, I'm afraid of people getting injured and dying, and I'm afraid of planes bombing our homes," he said.

-ABC News' Sami Zayara and Zoe Magee