Secretary of State Antony Blinken on Wednesday said Israel "cannot occupy" Gaza "not now, not after the war."

The top U.S. diplomat added that a transition period may be necessary when the bombings and shooting stop in Gaza.

"I think we've been very clear from day one that when it comes to post-conflict governance in Gaza, a few things are clear and necessary," Blinken said in Tokyo, where he's attending G7 meetings. "One, Gaza cannot continue to be run by Hamas. That simply invites a repetition of Oct. 7, and Gaza used as a place from which to launch terrorist attacks. It's also clear that Israel cannot occupy Gaza."

Blinken said G7 members stood united on the globe's major crises. The group's "first focus was the crisis in the Middle East." The group's joint communique called for "humanitarian pauses," short of a cease-fire.

"We all agreed that humanitarian pauses would advance key objectives to protect Palestinian civilians, to increase the sustained flow of humanitarian assistance, to allow our citizens and foreign nationals to exit, and to facilitate the release of hostages," Blinken said

-ABC News' Christopher Boccia and Joe Simonetti

President Joe Biden told ABC News' Karen Travers that he asked Israeli Prime Minister Benjamin Netanyahu "for a pause" in fighting during a phone call Monday.

"I didn't get a chance to talk to him today, but I did ask him for a pause…yesterday," Biden said.

When asked for a specific timeline of the pause, the president did not answer.

-ABC News' Justin Fishel and Karen Travers

Israeli Prime Minister Benjamin Netanyahu said Tuesday that Israel Defense Forces have "encircled" Gaza City and are "operating inside it."

"We are increasing pressure on Hamas every hour, every day," he said in remarks translated by Reuters. "We have killed thousands of terrorists, above ground and below ground."

Maj. Gen. Yaron Finkelman, the commander of IDF's Southern Command, said Tuesday they are fighting in "significant centers of the Gaza Strip."

"For the first time in a decade, the IDF is fighting in the heart of Gaza City," Finkelman said in a statement. "Today, at this very hour, our soldiers are eliminating terrorists, discovering tunnels, destroying weapons and continuing to advance into the center of the enemy."

Dr. Ghassan Abu Sitta, a British-Palestinian plastic surgeon, called the conditions of working in a hospital in Gaza right now "medieval."

"There's no pain relief," he told ABC News in a phone interview on Tuesday. "I mean, we operate on patients and then we give them all paracetamol. We've run out of morphine two weeks ago."

Abu Sitta, who has been working at the Shifa and Ahli hospitals in Gaza, said they have had to perform surgery on some children without proper anesthesia.

"These kids are traumatized," he said.

He has seen children who come in with no surviving family, he said.

"It really is heart-wrenching," he said. "From the minute you see them in the emergency room with no one around them, you realize."

-ABC News' Zoe Magee

At least three premature babies have died at the Al-Shifa Hospital in the Gaza Strip when a missile struck nearby and shut down the medical facility's backup generator, according to a doctor working at the hospital.

Dr. Ahmed Mokhallalti, the chief plastic surgeon at the hospital, told ABC News that the babies died when the power to their incubators was cut off Friday night into Saturday morning.

Mokhallalti said all of the hospital's ventilators were back up and running Sunday, but he expressed fear that more people would die at the hospital due to the relentless bombing.

Hospital officials said two patients in the hospital's intensive care unit also died on Sunday due to complications caused by the shelling.

The international humanitarian group Doctors Without Borders has made repeated calls for the shelling of hospitals in Gaza to cease.

"We are nearly sure that we are alone now. No one hears us," Dr. Mohammed Obeid of Doctors Without Borders said in a video statement from the Al-Shifa Hospital on Saturday.

Obeid said there are about 600 patients at the hospital who need medical care and need to be evacuated.

"The problem is [we need] to be sure we can evacuate the neonatal patients because we have 37 to 40 premature babies," Obeid said. "We have about 17 other patients in the ICU, and we have 600 postoperative patients who need medical care. So the situation is very bad. We need help."

-ABC News' Zoe Magee, Matt Gutman and Sami Zayara