President Joe Biden said Friday that the release of 24 hostages held by Hamas in Gaza is "just the beginning" of a plan to free 50 of the more than 230 captives over four days.

“It's only a start, but so far it's gone well,” Biden said in a televised address from Nantucket, Massachusetts, where he and first lady Jill Biden are vacationing.

He said Friday's hostage release is part of a deal "reached by extensive U.S. diplomacy, including numerous calls I've made from the Oval Office to leaders across the region," including calls with Israeli Prime Minister Benjamin Netanyahu, Egyptian President Abdel Fattah El-Sisi and the emir of Qatar.

“All of these hostages have been through a terrible ordeal, and this is the beginning of a long journey of healing for them,” Biden said. “Today has been a product of a lot of hard work and weeks of personal engagement.”

Biden said that under the deal, more hostages would be released over the next three days with 50 being "our goal." But he added, "We also will not stop until we get these hostages brought home and an answer to their whereabouts.”

The president said U.S. officials do not know when Americans -- including two women and 4-year-old Abigail Edan, whose parents were killed by Hamas terrorists -- will be among those that are released or their conditions. He added, “We expect it to occur” and that it’s his “hope and expectation” that it “will be soon.”

Biden said the four-day cease-fire that was negotiated for the release of the hostages will allow time to "accelerate and expand humanitarian assistance going into Gaza."

Speaking of the children freed on Friday, one just 2 years old, Biden said, “The teddy bears waiting to greet those children at the hospital are a stark reminder of the trauma these children have been through at such a very young age.”

6:03

Biden speaks after first group of hostages released

President Joe Biden addressed the American people Friday following the release of 24 hostages in a deal struck between Hamas and Israel.

-ABC News' Justin Gomez

There were 200 trucks carrying aid that entered Gaza through the Rafah border crossing on Friday -- the first day of the humanitarian pause.

Of those 200 trucks, 137 unloaded goods at the reception point for the United Nations Relief and Works Agency for Palestine Refugees in the Near East, the aid organization said. It was the largest single-day delivery of aid since Oct. 7, the agency said.

Also, 129,000 liters of fuel and four trucks of gas crossed into Gaza through the border, the U.N. said. President Joe Biden said Friday both fuel and cooking gas were delivered to Gaza.

Twenty-one critically injured patients from northern Gaza were also evacuated through the border.

-ABC News' Will Gretsky

Twenty-two of the 24 Israeli and foreign citizens released by Hamas on Friday were first taken to the Hatzerim Air Force base in Israel before being transferred by military helicopters to hospitals, where they are to be reunited with their families, according to the Israel Defense Forces.

Two Israeli citizens were taken directly to hospitals by ambulance, the IDF said.

The returning hostages were escorted by IDF personnel, including medical personnel, the IDF said. IDF representatives were with the family members of the hostages to give them regular updates on the release of their loved ones, the IDF said.

Israeli Air Force helicopters were waiting at Hatzerim base to fly the returnees to the hospitals, according to the IDF.

0:42

Names of first Israeli hostages released

Israel releases the names of the Israeli hostages that were released Friday, with ages ranging from 2 years old to 85 years old.

-ABC News' Matt Gutman

Thirty-nine Palestinian prisoners were released Friday evening in accordance with the deal between Hamas and Israel to free hostages in Gaza.

"Tonight we finished the first day of our mission to bring the abductees home," Rabbi Gondar Cathy Perry, commissioner of prisons, said in a statement. "We will continue in the coming days to act as much as is required of us in order to support the national effort."

Those who were released included female security prisoners and minor security prisoners, according to the Israel Prison Service.

They were released from three prisons: Damon, Megiddo and Ofer. Perry visited the prisons to oversee the operations, according to the Israel Prison Service.

-ABC News' Will Gretsky