An estimated 220,000 Palestinians are sheltering throughout 92 United Nations relief and refugee facilities Refugees facilities across the Gaza Strip, according to U.N. Secretary-General Antonio Guterres.

Guterres called for "rapid and unimpeded humanitarian access now," early Thursday morning, local time.

Hospitals in Gaza are working at full capacity and have run out of space for those "wounded from Israeli airstrikes" to be treated, the Palestinian-Gaza Strip Ministry of Health said in a press release Wednesday.

The Ministry called for urgent action to be taken to provide safe passage for medical supplies and to transfer the wounded. Health services have reached a critical stage, according to the release, with "medicines, medical consumables and fuel" expected to run out imminently.

An Israel Defense Forces spokesperson addressed a possible ground incursion in an interview with David Muir, as the "World News Tonight" anchor reports from Israel.

IDF Lt. Col. Jonathan Conricus told Muir Wednesday that the "carnage" in the kibbutz of Be'eri, where more than 100 bodies were found, "definitely put things into perspective."

Following Hamas' attack, 360,000 Israeli reservists have been called up and tanks and soldiers are amassing on the Gaza border.

"One could deduce that from the troops that we have called up that it is what they will be tasked to do," Conricus told Muir, adding that at the end of the war, Hamas "won't have the military ability to kill or hurt Israeli civilians ever again."

Asked whether there was any scenario where a ground incursion would not happen, Conricus responded that it's "difficult to say."

"I personally don't think so. But that matters less," he said. "Our job is to be prepared and have all the troops ready for whatever assignment and however it is decided to implement them."

Two U.S. officials familiar with the diplomatic efforts to free hostages told ABC News it appears that allies and partners in the Middle East in communication with Hamas are being helpful in advocating for their release.

The officials say Hamas has shown no real willingness to partake in diplomacy up to this point.

Hamas’ designation as a foreign terrorist organization also complicates any negotiations involving the U.S., because the official label makes it illegal for any American to knowingly provide "material support or resources," which includes personnel.

Deputy Special Envoy for Hostage Affairs Steve Gillen is among the U.S. delegation en route to Israel with the Secretary of State Antony Blinken.

In remarks earlier Wednesday, President Joe Biden said "there's a lot we're doing" to bring the hostages home.

"In the days ahead we're gonna continue to work closely with our partners in Israel and around the world,” he said.

-ABC News' Shannon K. Crawford

In remarks with Israeli Prime Minister Benjamin Netanyahu, Secretary of State Antony Blinken said at least 25 Americans had now been confirmed dead in Israel.

Netanyahu described some of the atrocities committed by Hamas.

"Hamas has shown itself to be an enemy of civilization: The massacring of young people in an outdoor music festival, the butchering of entire families, the murder of parents in front of their children and the murder of children in front of their parents. The burning of people alive, the beheadings," he said.

"Hamas should be treated exactly the way ISIS was treated," he said. "They shouldn't be spit out from the community of nations. No leader should meet them. No country should harbor them. And those that do should be sanctioned."

Blinken said he was speaking not only as an American diplomat, but as a Jew, a husband and a father of young children, saying it was impossible for him to look at photos of families killed "and not think of my own children."

"The same time that we've been shocked by the depravity of Hamas, we've also been inspired by the bravery of Israel citizens," he said. "The grandfather who drove over an hour to a kibbutz under siege, armed only with a pistol and rescued his kids and grandkids. The mother who died shielding her teenage son with her body, giving her life to save his -- giving him life for a second time."

Blinken remarked that some U.S. aid had already been delivered, and that more military aid was on his way. He said the administration would work with Congress to meet Israel’s additional needs and that bipartisan support for Israel was "overwhelming."

The secretary called on world leaders to condemn Hamas.

Blinken also reiterated that Israel "has the right -- indeed, the obligation -- to defend itself" but that it was "so important to take every possible precaution to avoid harming civilians."

-ABC News' Shannon Crawford