A "handful of Americans" are expected to leave Gaza on Wednesday and enter Egypt through the Rafah border crossing, National Security Council spokesperson John Kirby said.

According to the Palestinian Children's Relief Fund, five American aid workers crossed from Gaza into Egypt on Wednesday.

Kirby called the exit of Americans "a significant breakthrough."

Approximately 400 Americans, as well as 600 of their family members, have been trapped in Gaza, according to the State Department.

"We've gotten through a bottleneck," Kirby said, but the evacuations will "take some time."

He cautioned that "the situation remains very fluid" and explained the "complicated process" to identify Americans and make sure they have proper documentation and can access an available route to exit safely and efficiently.

President Joe Biden said later Wednesday afternoon, "American citizens were able to exit today as part of the first group of probably over 1,000. We’ll see more of this process going on in the coming days. We're working nonstop to get Americans out of Gaza, as soon and as safely as possible."

-ABC News' Justin Ryan Gomez

Secretary of State Antony Blinken will travel to Israel and Jordan on Friday, State Department spokesperson Matt Miller announced.

Blinken will meet with Israeli Prime Minister Benjamin Netanyahu and other Israeli leaders to get an update on their military plans.

While meeting with the Israelis, Blinken "will reiterate U.S. support for Israel's right to defend itself in accordance with international humanitarian law and discuss the need to take all precautions to minimize civilian casualties, as well as our work to deliver humanitarian assistance," Miller said.

In Jordan, Blinken will "underscore the importance of protecting civilian lives and our shared commitment to facilitating the sustained delivery of life saving humanitarian assistance to civilians in Gaza, the resumption of essential services, and ensuring that Palestinians are not forcibly displaced outside of Gaza," Miller said.

"He will also reaffirm the U.S. commitment to working with partners to set the conditions for a durable and sustainable peace in the Middle East to include the establishment of a Palestinian state that reflects the aspirations of the Palestinian people in Gaza and in the West Bank," Miller continued. "And of course, he will discuss the ongoing work to secure the release of all hostages.”

-ABC News' Shannon Crawford

Doctors Without Borders said 22 of its staff members -- all foreign nationals -- crossed into Egypt from Gaza via the Rafah crossing on Wednesday.

A new team of workers "is ready to enter Gaza as soon as the situation allows," Doctors Without Borders said. "Meanwhile, many of our Palestinian colleagues continue to work and provide lifesaving care in hospitals and across the Gaza Strip, while the most basic protections for hospitals and medical personnel are not guaranteed."

"We reiterate our call for an immediate cease-fire," the organization said. "Critically needed humanitarian supplies and staff must be allowed into Gaza where hospitals are overwhelmed and the healthcare system is facing total collapse."

Gaza's Jabalia refugee camp, the most populous refugee camp in the region, was hit by a second airstrike on Wednesday, according to the Hamas-run Gaza Health Ministry.

The Israel Defense Forces confirmed that on Wednesday, "based on precise intelligence, IDF fighter jets struck a Hamas command and control complex" in Jabalia, and that Hamas fighters were killed in the strike.

"Hamas deliberately builds its terror infrastructure under, around and within civilian buildings, intentionally endangering Gazan civilians," the IDF said. "The IDF has been urging Gazans in this neighborhood to evacuate as part of its efforts to mitigate harm to civilians. The IDF continues to call on all residents of northern Gaza and Gaza City to evacuate southwards to a safer area."

The IDF also took responsibility for the first strike on Tuesday, saying the blast killed a Hamas official who the IDF claimed was one of the leaders of the Oct. 7 attack on Israel.

The United Nations Human Rights Office said, "Given the high number of civilian casualties & the scale of destruction following Israeli airstrikes on Jabalia refugee camp, we have serious concerns that these are disproportionate attacks that could amount to war crimes."

Doctors Without Borders called for a ceasefire Saturday saying the conflict has reached "a new low in an endless stream of unconscionable violence." The organization, which has been providing medical care to people in Gaza, also condemned world leaders for not calling for a ceasefire.

"The deadly attack outside the gate of Al-Shifa hospital impacting an ambulance is horrendous. This is a lethal attack outside Gaza's main and busiest hospital, where our staff work daily to provide lifesaving medical care. We have repeatedly called for an immediate and total ceasefire, for the protection of healthcare facilities, as well as medics, patients and people who are taking shelter there," Doctors Without Borders said in a statement Saturday.

"This is a new low in an endless stream of unconscionable violence. The repeated strikes on hospitals, ambulances, densely populated areas and refugee camps are disgraceful. How many people have to die before world leaders wake up and call for a ceasefire?" Doctors Without Borders said.

This comes as the Palestinian death toll rises to 9,488 -- including 3,900 children and 3,509 women -- and 24,158 Palestinians were injured, according to the Hamas-run Gaza Health Ministry.

One physician described seeing an ambulance hit outside Al-Shifa hospital.

"We were standing inside the hospital gate when the ambulance was directly hit in front of us. There were bloody bodies everywhere. Many were killed immediately, while we rushed others to the operating room for emergency care," Dr. Obaid, a Doctors Without Borders doctor at Al Shifa hospital, said.

The Israel Defense Forces claimed its aircraft hit an ambulance that it believes was being used by Hamas and called for civilians to move south for safety.

-ABC News' Cindy Smith and Emma Ogao