President Joe Biden spoke with Israeli Prime Minister Benjamin Netanyahu on Sunday about the latest developments in Gaza, including the release of more hostages, the White House said.

"The President welcomed the release of hostages by Hamas over the past three days, including a young American girl. The two leaders also discussed the pause in the fighting and surge in much needed additional humanitarian assistance into Gaza," the White House said.

The Israeli prime minister's office also issued a statement following their conversation, saying they spoke with "great excitement" about the hostages who were released, including 4-year-old Abigail Idan.

"What a joy to see her with us. But on the other hand, what a pity that she returns to the reality of not having parents. She has no parents -- but she has a whole nation that embraces her and we will take care of all her needs," Netanyahu's office said.

-ABC News' Justin Ryan Gomez

Alma Avraham, an 84-year-old Israeli hostage released by Hamas Sunday, was taken to Soroka Medical Center in Beersheba in "serious condition," IDF spokesman Daniel Hagari said.

"Alma, who was returned to us in serious condition, was immediately evacuated by helicopter to the hospital. She was evacuated by IDF troops while still inside Gaza,” he said during a press conference.

Due to "medical reasons" and to ensure the safety of the hostages, 13 of them were escorted out of Gaza by special forces near the community of Be'eri, "in full coordination with Egyptian security authorities," Hagari added.

In a short statement, Soroka said Avraham is in "poor physical condition and severe clinical condition."

The IDF and General Security Service killed five senior Hamas officials in Gaza, IDF spokesman Daniel Hagari said Sunday, adding they were "key figures and key partners" in the Oct. 7 attack.

Hagari also said the war will not end until all the hostages are returned.

"This is the ethical and moral duty of every IDF soldier and the bodies of the defense establishment," he said.

Israeli Prime Minister Benjamin Netanyahu toured the Gaza Strip on Sunday and vowed the return of all of the hostages taken by the Hamas terror group, according to the prime minister's office.

Netanyahu spent time with Israeli commanders and fighters and visited one of the Hamas tunnels uncovered by Israeli forces, the prime minister's office said in a statement.

"We are here in Gaza with our heroic fighters," Netanyahu said in a video released by his office showing him wearing a helmet and flak jacket, and surrounded by Israeli soldiers. "We make every effort to return our abductees, and eventually we will return them all. We have three goals for this war: eliminate Hamas, return all our abductees, and ensure that Gaza does not become a threat to the State of Israel again."

Netanyahu added, "We continue until the end -- until victory. Nothing will stop us, and we are convinced that we have the power, the strength, the will and the determination to achieve all the war's goals, and we will."

-ABC News' Bruno Nota and Jordana Miller

Hamas has accused the Israeli military of arresting the director of Al-Shifa Hospital, the largest medical complex in the Gaza Strip, along with several other staff members "who remained at the facility to help patients and wounded evacuate."

"We see this move by Israel as nothing less than despicable, lacking any sense of humanity and morals," Hamas said in a statement on Thursday morning. "It is also a flagrant violation of international norms and charters, given obligations to ensure that medical personnel are never harmed, including in times of war."

Hamas noted that Al-Shifa Hospital's director, Dr. Muhammad Abu Salamiya, was in contact with International Committee of the Red Cross and the World Health Organization "to evacuate the remaining patients and wounded." The militant group, which rules Gaza, called on the ICRC, the WHO and other international bodies "to exert pressure on the Israeli occupation army to secure his release, along with the medical personnel who were arrested simply for continuing to fulfil their humanitarian duty."

In a separate statement on Thursday, Gaza's Hamas-run Ministry of Health said the arrests occurred Wednesday as the United Nations and its health arm, the WHO, led a convoy of evacuated patients and medical staff from Al-Shifa Hospital. Israeli soldiers "stopped the convoy at a checkpoint separating the northern and southern Gaza Strip for seven hours" before arresting the hospital director and other staff members, according to the health ministry.

"The [Israeli] occupation bears full responsibility for the lives and safety of detained colleagues," the ministry added. "The United Nations bears full responsibility for what happened, and we await measures on their part to address this. We decided to stop coordination with the World Health Organization until a report on what happened was submitted and all detainees were released."

There was no immediate confirmation of the event or comment from the U.N. or the WHO.

There was also no immediate confirmation of the arrests or comment from the Israel Defense Forces, which has been conducting a ground raid of Al-Shifa Hospital in Gaza City for days.

The IDF alleges that Hamas has placed its command centers under Al-Shifa and other hospitals in Gaza and is deliberately sheltering behind Palestinian civilians -- claims that the militant group denies.

-ABC News' Nasser Atta and Morgan Winsor