The U.S. believes there are eight or nine Americans still being held in Gaza, National Security Council spokesperson John Kirby said, adding that the U.S. does not have "solid information on each and every one of them."

Asked if Americans were expected to be released in the coming days, Kirby said the administration "certainly hope[s] so," but did not say more.

"I mean, we're going to watch this very, very closely. We're certainly hoping that another batch of hostages gets released today as part of the fourth and final day of the original agreement. We’re going to be watching closely to see if any Americans are in that group," Kirby said.

"We don't really know until you get into the end game who's going to be actually on that list and then, even then, you got to watch closely [to see] if who's on the list is folks that actually come out," he said.

Kirby was asked specifically about the two American women who were expected to be part of the first round of releases, and he reiterated his hope they would be released Monday.

-ABC News' Molly Nagle

Hamas officials said they've received a list of Palestinian prisoners who are expected to be released from Israel on Monday in exchange for hostages. The list includes three women and 30 children, Hamas officials said.

Muhammad Ibrahim Asfour was among the Gaza residents who returned home during the cease-fire to find destruction where homes used to be.

"I was shocked, and when I saw the house I started crying," Asfour told ABC News. "There were 50 people in the building here -- all of my brothers and father were living here."

"The situation here is more difficult than you can imagine," Abdelkader Darma told ABC News. "When I came home I was shocked."

"People do not know where to go," Darma said. "I and six other people slept on two mattresses and two pillows, which means you do not know how to sleep. They sleep three against three, and you find his feet in front of your face."

“I hope the truce will be extended and a solution will be found because it is enough. People are sleeping in the street," Darma said. "How can you bear it?"

-ABC News' Zoe Magee and Sami Zayara

Majed Al-Ansari, spokesperson for Qatar's Ministry of Foreign Affairs, said an agreement has been reached to extend the humanitarian truce between Israel and Hamas for two more days.

Hamas said this truce is "under the same conditions as the previous truce."

Diaa Rashwan, chairman of Egypt's State Information Service, said earlier on Monday that the deal would involve the release of 10 Israeli women and children being held hostage by Hamas in exchange for 30 Palestinians detained in Israeli prisons each day of the extension.

Yifat Zailer, a relative of one of the youngest Israeli hostages still being held in the Gaza Strip, said Tuesday that she has yet to hear whether her missing family members will be among those released by Hamas as part of the truce.

"The pain of not having them back yet is incredible. Tomorrow is the last day of this deal of cease-fire and we are very concerned," Zailer told ABC News' George Stephanopoulos in an interview on "Good Morning America."

Zailer said there has been no word from Israeli officials or others on whether her loved ones will be included in the prisoner swap with Hamas. The last thing she heard about her missing relatives was in a recent statement released by the Israel Defense Forces that stated there was a possibility of another Palestinian militant group holding them hostage.

"We are completely at loss," she said. "We don't know about their condition, we don't know if they're still alive even and it’s unbearable. They promised in this deal they signed, all the sides, that all mothers and children are supposed to be released."

"Prisoners are being released," she noted. "Where's my family?"

Four of Zailer's relatives -- her 32-year-old cousin Shiri Babas, Shiri's 34-year-old husband Yarden and the couple's children, 4-year-old Ariel and 10-month-old Kfir -- were kidnapped from their kibbutz in southern Israel during Hamas' attack on Oct. 7 and taken hostage to Gaza. Zailer said she doesn't understand why they -- especially the baby -- are still being held hostage and wondered whether it was for "leverage."

"Kfir is going to be 11 months [old] soon. He was kidnapped when he was 9 [months old]. We don't know how he's being fed," she told ABC News. "Why aren't they on any list? Every night we receive that phone call that they're not coming back tomorrow is torture -- it's psychological torture."

When asked whether she would support a deal for Israel to release all of its Palestinian prisoners in exchange for the hostages in Gaza, Zailer said: "That's a really hard question, but I must say I am."

"All those hostages are fathers, mothers, injured people and, of course, my family members as well among them," she continued. "So there's no price for our loved ones."

Zailer said she wants the world to know that her captive relatives "are and always were people of peace" and "innocent civilians."

"My uncle raised his daughter to love who's different from her," she added. "She's an incredible mother, her husband is an incredible father."

-ABC News' Morgan Winsor