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

Eighty-eight workers with UNRWA, the United Nations agency for Palestinian refugees, have been killed since Oct. 7, the highest number ever seen in a single conflict, the agency said.

A UNRWA spokesperson said the 88 fatalities are "only what we could verify -- the actual number could be even higher."

"Like most Gazans, our staff have also lost relatives, friends, neighbors and are themselves displaced with their families," UNRWA said. "And yet, they continue to work tirelessly to provide humanitarian assistance."