National Security Council spokesman John Kirby remained tightlipped on the possible hostage deal, telling reporters Tuesday, "We're all hopeful, but we won't say and do not want to say, anything in these delicate hours that could put a deal at greater risk."

If a deal is reached, Kirby said the first step would be to secure safe passage for the hostages into Israel, where many would likely need immediate medical attention before they return to their home countries.

Pressed by ABC News about how long it could take for the safe passage to be secured and hostages released after a deal is reached, Kirby said, "Depending on if we get a deal, depending on how many hostages are arranged for, depending on where they are, depending on their physical condition and their mobility, I think we all need to be humble in terms of the appropriate amount of time it could take to physically move them to safety."

"Some of these people could be in pretty rough shape. I think we all need to be prepared for the fact that it could take hours, if not days, to complete their release," he said.

-ABC News' Molly Nagle

Three doctors were killed in a strike at northern Gaza's Al-Awda Hospital, according to Doctors Without Borders.

The hospital said only medical personnel, patients and the injured were inside the facility at the time.

Hospital officials called on the international community to provide a safe corridor for the evacuation of patients and medical staff.

"We mourn the loss of our colleagues," Doctors Without Borders said in a statement. "We condemn this strike in the strongest terms, and call yet again for the respect and protection of medical facilities, staff and patients. We reiterate our call for an immediate cease-fire to prevent more deaths in Gaza."

Israel hopes to secure the release of at least 50 hostages within four days, according to a senior Israeli official with knowledge of the negotiations.

The official told ABC News on Tuesday that all Israeli security forces and agencies are in favor of the proposed deal with Hamas, which was brokered by Qatar.

For two weeks, Israel was against accepting Qatar's original offer, the official said. Among other things, the government did not want to allow people to return to northern Gaza during the cease-fire period, the official said. Israel also wanted to limit the entry of fuel into Gaza to only the days of the cease-fire, according to the official.

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Israel faces ‘unprecedented’ hostage crisis ahead of vote on potential deal

Dani Gilbert, an assistant professor of political science at Northwestern University, joins ABC News Live anchor Stephanie Ramos to discuss the latest on hostage negotiations in Israel.

-ABC News' Jordana Miller

A U.S. official told ABC News the hostage deal would involve Hamas releasing 50 women and children in exchange for a pause in fighting that would last four or five days. The deal would also involve the release of three Palestinian prisoners for each Israeli hostage, the official said.

The Palestinian prisoners are not considered hostages. Some of them were imprisoned prior to the conflict.

The official cautioned that the deal is not done. President Joe Biden has been personally involved in the negotiations, urging the emir of Qatar to press Hamas to accept the deal and urging Israeli Prime Minister Benjamin Netanyahu to accept the deal, according to the official.

-ABC News' Selina Wang