Israel-Gaza live updates: 6 killed after Israeli operation in West Bank

The National Security Council is pushing back on claims the U.S. is being to optimistic about a cease-fire deal between Israel and Hamas, stressing that it is "actively engaging counterparts in Qatar, Egypt, Israel, to see what we can do to try to move this forward," spokesperson John Kirby said Thursday.

Kirby said 90% of a deal has been agreed to.

"You call that optimistic. I call that accurate. That's how close we believe we are. That's where we have gotten to. The basic framework of the deal has been agreed to," Kirby said.

"What we're talking about now is the implementing details, and specifically the exchange of prisoners. And now that calculus is different because of what happened over the weekend," he said, referring to the death of six hostages in Gaza.

Kirby acknowledged that the administration is "frustrated that we still haven't been able to conclude this deal."

"We believe that these differences can be resolved. What the next step looks like in terms of resolving them? I think we just don't know right now," Kirby said.

"We want to see the hostages home as soon as possible. But I would also say that as frustrating as it has been at times and as unhelpful as not just public comments, but even private machinations in the negotiation process have been to closure of the deal, it has not dimmed one bit President Biden's commitment to trying to see this through," he said.

-ABC News' Molly Nagle

Five people were killed after Israeli strikes hit a location "in the humanitarian area in Deir al-Balah," near the Al-Aqsa hospital, according to the Gaza Ministry of Health and Israeli Defense Forces.

Israeli forces were conducting a "targeted strike on terrorists who operated in a Command and Control Center," used by Hamas and the Islamic Jihad there, the IDF said in the release.

-ABC News' Jordana Miller and Sami Zyara

Six people were killed in the Tubas and Far'a neighborhoods in the West Bank after an Israeli operation was carried out overnight, the Israel Defense Forces and Palestinian Ministry of Health said in statements Thursday.

The IDF called the operation in Tubas and Far'a a "counterterrorism operation."

Since the IDF operation began last week, 39 people have been killed and about 145 people have been injured in the West Bank, the Palestinian Ministry of Health said.

Israeli Defense Minister Yoav Gallant said the government must "remain focused" on the "resurgence of terrorism in the West Bank," in remarks Thursday.

-ABC News' Jordana Miller and Nasser Atta

The polio vaccination campaign in Gaza is making "great progress," according to United Nations Relief and Works Agency for Palestine Refugees in the Near East Commissioner-General Philippe Lazzarini.

The World Health Organization said the next phase of the campaign begins Thursday in southern Gaza targeting an estimated 340,000 children under 10.