Releasing more hostages will be a "prime" focus of Secretary of State Antony Blinken's latest trip to the Middle East, the White House said.

"We're up around 70 or so hostages out so far, which is good. It's a good start, but it's just a start. There are many more," White House National Security spokesperson John Kirby told reporters Tuesday. "We want to get them all back."

Blinken will also meet with his Israeli counterparts to reassure them of U.S. support and talk about getting humanitarian assistance to Gaza, Kirby said.

This week's trip will be Blinken's fourth to the region since the Oct. 7 attack.

-ABC News' Cheyenne Haslett

The United States delivered more than 54,000 pounds of medical and food aid for Gaza in a flight to Egypt earlier Tuesday, according to National Security Advisor Jake Sullivan.

Two more planes are set to make deliveries in the coming days, he said.

"The humanitarian needs in Gaza demand that the international community do much more," Sullivan continued, adding that the U.S. is committed to keeping that aid up.

-ABC News' Cheyenne Haslett

Twelve hostages are back in Israeli territory in the latest exchange, according to the Israeli government.

The hostages include 10 Israelis and two foreign nationals, both from Thailand, officials said.

The Israeli citizens were identified as Tamar Metzger, 78; Ditza Hayman, 84; Norlin Babdila, 60; Ada Sagi, 75; Ophelia Edith Roitman, 77; Rimon Kirsht, 36; Merav Tal, 53; and the Leimberg family -- Gabriella Leimberg, 59, Mia Leimberg, 17, and Clara Marman, 63.

The IDF said the hostages were taken through Egypt before heading to a meeting point in Kerem Shalom, in Israel.

Five of the women -- Metzger, Hayman, Ada Sagi, Roitman and Tal -- were residents of Kibbutz Nir Oz, one of the communities hit hardest by Hamas' Oct. 7 attack.

"They were held captive, in harsh conditions and deprived of essential medical care. Two of the women released have been separated from their husbands, who remain in captivity," the kibbutz said in a statement. "The Nir Oz community is committed to support them, and their families, through the long recovery process ahead."

Thirty Palestinian prisoners were released in exchange for the hostages, according to Qatari officials.

-ABC News' Will Gretsky

Abigail Idan, the 4-year-old American-Israeli hostage who was released by Hamas on Sunday, has been discharged from Schneider Children's Medical Center, hospital officials said.

"Since her arrival, the medical and psychosocial team at Schneider accorded her all-embracing medical and emotional care," officials said.

President Joe Biden said Monday that he "spoke with Abigail’s family following her release, and we are working closely with our Israeli partners to ensure she gets the care and support she needs as she begins to recover from this unspeakable trauma."

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