Israel-Gaza live updates: Israeli officials on reports of Russian airport protesters

President Joe Biden and Israeli Prime Minister Benjamin Netanyahu spoke Sunday about "developments in Gaza," and the president reiterated that Israel needed to defend itself "in a manner consistent with international humanitarian law," according to the White House.

The two also discussed efforts to locate and free hostages, including U.S. citizens, the White House added.

Biden also spoke with Egyptian President Abdel Fattah El-Sisi on Sunday, the White House said, and the two "committed to the significant acceleration and increase of assistance flowing into Gaza beginning today and then continuously."

The two leaders talked about "ensuring that Palestinians in Gaza are not displaced to Egypt or any other nation," the White House added.

-ABC News' Fritz Farrow

Abood Okal, a 36-year-old American father trapped in Gaza with his wife and young son, told ABC News on Sunday about the difficulties getting drinking water and bread.

"And I think it is for many people here in Gaza. We are almost out of drinking water today," he said. "I think we have enough just to last us through the night and then tomorrow would be basically out."

Okal described them spending their days not only "trying to figure out our water situation," but also trying to secure bread, telling ABC News he was part of a group that spent six hours standing in lines in front of bakeries.

"We hit four different bakeries to buy bread and any type of bread, actually, and it was a total mayhem, just like we expected," he said. "And actually quite heartbreaking to see the amount of people lined up in front of the bakeries, hundreds and hundreds of people in front of each one."

Okal said they stood in line for hours to get one portion of bread -- "which is about 25 to 30 pieces of pita bread, an average sized pita bread," he said -- "which basically would be good enough for a day or two at most."

"I think Gaza has reached a point where it does not matter where you're from or how much money you have or who you know," he said. "Everyone is in the same boat in terms of the dire daily struggle to survive. And certainly our family is no exception to that."

-ABC News' Zoe Magee

Securing the release of the hostages being held in Gaza is still a priority as Israel expands its ground assault in the territory in an effort to defeat Hamas, the White House's national security adviser said Sunday.

"We are continuing to see if there are ways to make that happen. We are prepared to support humanitarian pauses so that hostages can get out safely. And we will keep working at that every day because the president has no higher priority than the safe return of American citizens and wants to support the return of citizens of other countries and Israelis, as well," Jake Sullivan told ABC "This Week" co-anchor Martha Raddatz.

"Now, how exactly that happens ... I cannot predict that. All I can tell you is every effort is being undertaken right now to do that," Sullivan said.

But he noted "there are ongoing efforts which I can't get into detail on television, including regional partners, including the Israelis."

-ABC News' Tal Axelrod

7:54

US is ‘prepared to support humanitarian pauses’ to free hostages: Jake Sullivan

ABC News’ Martha Raddatz interviews National Security Adviser Jake Sullivan on “This Week.”

ABCNews.com

Israel's expanding ground assault on Gaza will involve months of painstaking and "very fierce fighting" with Hamas extremists amid conditions "unlike anything that we’ve seen in recent years," retired Army Gen. Robert Abrams predicted on Sunday.

"And simultaneously trying to ensure that the Israelis do not target, unwittingly, the locations on the hostages -- this is going to prove to be a very difficult task," Abrams told ABC "This Week" co-anchor Martha Raddatz. "And we’ll just have to see how their plan plays out here over the coming days."

Abrams, who commanded U.S. troops during America's invasion of Afghanistan and Iraq, went on to say that he believes Israeli forces face a nigh insurmountable challenge in their stated goal to destroy the militant group that launched a terror attack on Israel earlier this month -- while seeking to limit civilian casualties in the Palestinian territory and recover the hundreds of captives Hamas is thought to be holding in Gaza.

"It’s going to be what I would consider nearly impossible to destroy Hamas, to eliminate their capability to do harm to Israel and the Israeli people, while simultaneously protecting what some people have estimated as to be a million Palestinians who are in harm’s way and they can’t get out of harm’s way," Abrams said.

6:08

Israeli ground incursion will ‘take a long time’: Gen. Robert Abrams

ABC News’ Martha Raddatz interviews retired Gen. Robert Abrams on “This Week.”

ABCNews.com

Israel has faced mounting international outcry at the potential humanitarian disaster in the blockaded territory as it carries out its retaliatory operations on the militants.

Abrams said on "This Week" that he thinks "every effort is being made to follow the laws of armed conflict" but acknowledged the "horrific" images being broadcast of the escalating conflict.

"Fundamentally, at the end of this, Martha ... we still have to answer the question: What is the future? Hamas was created as a result of a lack of a separate Palestinian state. A two-state solution, as many people have talked about. That has to be somewhere, when you asked, 'How does this end?' That has to be part of the equation," Abrams said.

-ABC News' Adam Carlson