Israel-Gaza live updates: Israel 'deepening the war' in Gaza: Netanyahu

Israeli forces -- which are "almost in full operational control" of northern Gaza -- are continuing to fight on the ground in the southern Gaza city of Khan Younis, and are now "preparing to expand operations" to more parts of southern Gaza, said Israel Defense Forces spokesperson Rear Adm. Daniel Hagari.

This week, in Issa in the south of Gaza City, Hagari said Israeli forces found and destroyed an underground tunnel that was hundreds of meters long and had command and control rooms.

Asked about Israel’s investigation into how Hamas pulled off its Oct. 7 attack, Hagari noted, "Some areas of [Hamas'] tunnels were attacked in the past and restored -- we will examine why we estimated that the restoration would take longer."

The surviving members of Kibbutz Reim have relocated as a unified group to temporary housing in Tel Aviv. The move creates a "first-of-its-kind urban kibbutz," according to a statement from the kibbutz.

The families will live in a compound that includes two buildings and a community center, similar to what the original kibbutz had. The new temporary housing will also connect the survivors to services including psychological support and a local school.

-ABC News’ Becky Perlow

National Security Council spokesperson John Kirby said the U.S. is “leading the world” in getting humanitarian aid to Gaza, where the crisis worsens by the day.

“Nobody can look at the images coming out of Gaza and … not feel a sense of pain and anguish for so many innocent people that have been displaced from their homes, families killed, many wounded,” Kirby said.

ABC News asked Kirby about a letter sent to President Joe Biden this week from a group of House Democrats that raised concerns with Israel's military operation in Gaza. The lawmakers called the civilian death toll in Gaza unacceptable and urged Biden to work to shift Israel’s strategy.

Kirby acknowledged, “We don't believe you're going to be able to wipe out the ideology that inspires Hamas through military action."

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UN says more than half a million people in Gaza are starving ABC New’s foreign correspondent Britt Clennett reports from Tel Aviv, Israel, on the latest cease-fire and hostage negotiations as the humanitarian crisis gets worse in Gaza.

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-ABC News’ Lauren Peller

National Security Council spokesperson John Kirby said there have been "serious talks and negotiations over trying to get back into another pause and a hostage exchange."

“It won’t get lost over the holidays. We're working on it every single day, almost every hour of every day," Kirby said.

Kirby said the Israelis recognize that "they need to transition" to a lower intensity stage of fighting.

"They have said themselves that they realize they're going to have to transition from a higher intensity level of operations, such as what they're doing now, to something a bit lower intensity. They will decide when, they will decide what lower intensity looks like, and what that means," he said.

Kirby said the U.S. is "not dictating the terms and timelines to the Israelis" on moving to lower intensity military operations.

-ABC News’ Lauren Peller