During President Joe Biden's call Thursday with Israeli Prime Minister Benjamin Netanyahu, the president noted that "it was Hamas’s refusal to release young women civilian hostages that led to" the end of the multiday cease-fire, according to a White House readout of the leaders' call.

Biden "reiterated that the [International Committee of the Red Cross] must be permitted to access remaining hostages held by Hamas terrorists," the White House said, and Biden and Netanyahu "agreed to remain deeply engaged to pursue every possible opportunity to free the remaining hostages."

Biden also stressed the importance of humanitarian aid into Gaza. Biden "welcomed the recent Israeli decision to ensure that fuel levels will meet requisite needs, but stressed that much more assistance was urgently required across the board," the White House said.

Biden again noted the need to separate civilians in Gaza from Hamas, the White House said, and the president reiterated his concern about the "extremist violence committed against Palestinians and the need to increase stability in the West Bank."

-ABC News' Fritz Farrow

National Security Council spokesperson John Kirby said he could not confirm reports that Hamas has sexually assaulted hostages, but he said the reports are "believable."

"I can't confirm these individual reports and stories," Kirby said, calling them "horrific."

"Sadly, because of who we're dealing with, we certainly aren't in a position to disabuse these reports," Kirby continued. "And the truth is, they're believable, just on the face of it, because of who these guys are, and what they believe. And because we have heard other accounts from other survivors that have come back and other hostages."

According to Israeli officials, 138 people are still being held hostage by Hamas. Over 100 women and children have been released.

"We know that Hamas is holding some additional women and children," Kirby said. "Let's get the remaining women and children out and get them out from under the jackboot of Hamas and potential sexual violence."

-ABC News' Fritz Farrow

National Security Council spokesperson John Kirby told ABC News on Thursday that involved parties are "not close" to a deal for additional pauses to secure the release of hostages.

"Talks are still ongoing, discussions are happening. … I wish I had specific progress to speak to -- I don't," Kirby said.

"We're not close to inking another deal on a humanitarian pause," he said, "nor do I have any news to break here today about the return of hostages."

"We’re still trying to get as much information as we can about the hostages being held," Kirby said. "We have some information, as I said before on some of the hostages, because their families are talking to us, and that's been a terrific source of information and context."

"We have less information on others," Kirby added. "But not for lack of trying."

-ABC News' Fritz Farrow

There are "some promising signs" in the negotiations to open the Kerem Shalom crossing from Israel into Gaza for humanitarian access, according to Martin Griffiths, the United Nation's under-secretary-general for humanitarian affairs and emergency relief coordinator.

"There are promising signs now that that may be able to open soon," Griffiths said. "If we get that, well, it would be the first miracle we've seen for some weeks, but it would be a huge boost to the logistical process and logistical base of a humanitarian operation. It doesn’t mean to say that it will solve the security problems … but it will change the nature of humanitarian access."

Aid trucks are still crossing daily through the Rafah border crossing from Egypt into Gaza as Gaza's humanitarian crises worsens, Griffiths said, but many roads along that route have been destroyed, making access difficult.

The Israel Defense Forces said Monday that it is expanding its ground offensive to the entire Gaza Strip amid its ongoing war against Hamas.

"We have entered a new phase in our war against Hamas," IDF spokesperson Rear Adm. Daniel Hagari said in a video statement. "We pursued them in northern Gaza. We're now pursuing Hamas in southern Gaza, too."

"As we expand our operation in Gaza, we remain committed to our goals: secure the release of our hostages and dismantle Hamas," he continued. "We will operate in maximum force against Hamas terrorists and infrastructures while minimizing harm to the civilians that Hamas places around them as shields."

Hamas, the Palestinian militant group that governs Gaza, which is home to 2.3 million people, has denied Israel's claims that it deliberately shelters behind civilians by hiding its fighters, infrastructure and weapons in hospitals, schools and other areas populated by civilians.

Hagari said the IDF used the seven-day pause in hostilities with Hamas last week "to increase readiness, review intelligence and refine operational procedures."

"We are implementing lessons learned for the new phase of this war, improving the efficiency and precision of our operations on the ground," he added. "We are pursuing Hamas wherever Hamas is hiding, in the north and in the south. Every rocket launcher, weapons depot, command and control center, senior commander, underground infrastructure and any hideout where our hostages may be held."

Hagari maintained the Israel's "war is against Hamas, not against the people of Gaza" and that "every civilian death is a tragedy -- a tragedy that the IDF does not want and is taking extensive measures to avoid." More than 15,500 people have been killed by Israeli forces in Gaza since Oct. 7, according to figures released by Gaza's Hamas-run Ministry of Health and the Hamas government media office.

The IDF is "dropping leaflets with QR codes that opens a map guiding Gazans to safer areas," according to Hagari. However, the Israeli bombardment has disrupted telecommunications in Gaza and a majority of the population does not have access to internet or phone service.

"The map is divided into neighborhood numbers indicating where civilians in a specific area should go to avoid being in the crossfire," he said. "We call on international organizations in Gaza to assist us with this effort. It can help save lives."

-ABC News' Morgan Winsor