After Hamas' armed wing announced that it will be delaying the scheduled release of hostages, it said it is going ahead following mediation by Qatar and Egypt. Hamas also released a list of the Palestinians set to be released -- six women and 33 teenagers.

"Hamas has responded to the Egyptian and Qatari efforts made throughout the day to ensure the continuation of the temporary truce agreement after they affirmed the occupation’s commitment to all terms set out in the agreement," the terrorist group said Saturday.

Qatar's Ministry of Foreign Affairs said the swap will happen Saturday night.

"After a delay in implementing the release of prisoners from both sides, the obstacles were overcome through Qatari-Egyptian communications with both sides, and tonight 39 Palestinian civilians will be released in exchange for the release of 13 Israeli detainees from Gaza in addition to 7 foreigners outside the framework of the agreement," Majed Al Ansari, the Qatari MFA spokesperson, said in a statement on X on Saturday.

-ABC News' Matt Gutman and Ayat Al-Tawy

In response to news that Hamas will delay the release of hostages, with the terrorist group accusing Israel of violating the cease-fire agreement, the Biden administration said it is working on the implementation of the deal.

"We are working with Qatar, Egypt, and Israel on implementation of the deal," a senior administration official told ABC News.

-ABC News' Selina Wang

Doctors Without Borders released a statement calling for an extension for a sustained ceasefire, saying that four days is not enough.

"After being under relentless bombing for more than six weeks, any respite for the people in Gaza is welcome, especially if it allows them to have access to medical supplies, food, and water," Doctors Without Borders said in a statement.

"Four days, however, is not nearly enough to organize a delivery of aid that can measure up to the immense needs. We remain deeply concerned at the prospect that after a short-lived relief, people will fall back into a sealed-off complete war zone," it added. "We continue to call for a sustained ceasefire as the only way to stop indiscriminate killings and civilian harm and allow the delivery of desperately needed humanitarian aid on a meaningful scale."

-ABC News' Zoe Magee

Israeli Defense Forces' Chief of Staff Lt. Gen. Herzi Halevi said the military will immediately return to striking the Gaza Strip once the ceasefire with Hamas ends. Halevi told soldiers the ceasefire and hostage deal would not have happened without the IDF’s pressure on Hamas.

"We do not intend, do not want, and are not ready to stop this effort before we return all the hostages… it is our moral duty to bring them back,” he said. adding the IDF will use the pause in fighting to "study, to better prepare our abilities and also to rest a little."

"And we will return immediately at the end of the ceasefire to attacking Gaza, to maneuver in Gaza. We will do it to dismantle Hamas and also to create great pressure to return as quickly as possible and as many hostages as possible, down to the last one of them," he said. "We have an obligation to fight and also to risk our lives so that [Israeli citizens] can return to live in safety, and we have hostages that we will do everything to bring them home."

As he toured the Gaza Strip Saturday, Israeli Defense Minister Yoav Gallant told Israeli commanders and soldiers that its forces will not leave the Gaza Strip until all of the hostages are returned to Israel, and any future negotiations with Hamas will be carried out amid the fighting.

"We will not leave Gaza until all the hostages are brought back home. We will find the opportunity to bring [home] additional hostages; any negotiation will be held under fire," he said. "We cannot leave Gaza and stop the war until we reach a situation in which we bring back all the hostages -- because we have many more [held captive]."

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.”

-ABC News' Justin Gomez