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."

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