The World Health Organization described the destruction in Khan Younis as "disproportionate to anything one can imagine."

Nasser Medical Complex -- once the "backbone" of the health system in southern Gaza -- Al-Amal and Al-Khair hospitals are "non-functional," according to WHO Director-General Tedros Adhanom Ghebreyesus.

"These facilities have no oxygen supply, water, electricity or sewage system," he said Thursday on X, a day after WHO team members and partners went to Khan Younis to assess health facilities following the withdrawal of Israeli troops from the city.

Jordanian Field Hospital was found to be "minimally operational," he said.

"The once robust health system in Gaza is broken," Ghebreyesus said. "WHO and partners stand ready to support reconstruction and rehabilitation efforts, but we need a ceasefire. Nothing else can bring a lasting and humane outcome."

Israeli military spokesman Rear Adm. Daniel Hagari told reporters Thursday that Israel is constructing a new land crossing from Israel into northern Gaza to facilitate more aid deliveries.

The Erez crossing, a key pedestrian crossing that was destroyed by Hamas on Oct. 7, will remain closed.

Last week, Israeli Prime Minister Benjamin Netanyahu said he would reopen the crossing for aid after speaking with President Joe Biden following the deaths of seven World Central Kitchen workers by an Israeli airstrike.

Although the timetable for the opening of the new land crossing wasn't revealed, Hagari said it would be located near the Erez crossing but not in the exact same spot.

Hagari said he expected 58 trucks would pass through the new crossing daily.

-ABC News' Will Gretsky

Following USAID Administrator Samantha Power acknowledging that famine is happening in northern Gaza, the White House was pressed Thursday on whether this could have been prevented if they had pressured Israeli Prime Minister Benjamin Netanyahu sooner to increase deliveries of humanitarian aid.

The U.S. has often called on Israel to open more crossings and allow for more aid to reach Gaza, but it wasn't until last week when President Joe Biden told Netanyahu that U.S. policy on Gaza hinges on Israel announcing and implementing measurable steps to address civilian harm, humanitarian suffering and the safety of aid workers.

"Every time the president has spoken to the prime minister there's -- part of that conversation has been to do more humanitarian aid," White House press secretary Karine Jean-Pierre said when asked if it was a mistake not to push Netanyahu to open the Ashdod port and Erez crossing sooner to help prevent famine.

She was asked specifically who is to blame for famine in Gaza, but she didn't attribute it to anyone, instead saying the focus is going to be on getting aid in.

"The humanitarian situation in Gaza, obviously, is dire. And that is why the president is doing everything that he can to get more humanitarian aid in," she said. "And that's what our focus is going to be."

-ABC News' Justin R. Gomez

The State Department revealed that U.S. government employees and their family members are now prohibited from undertaking any personal travel in Israel outside of the greater Tel Aviv, Jerusalem and Be’er Sheva areas "until further notice."

The alert says the restrictions were imposed "out of an abundance of caution" and shared to help other Americans in Israel make their own security plans.

"In response to security incidents and without advance notice, the U.S. Embassy may further restrict or prohibit U.S. government employees and their family members from traveling to certain areas of Israel (including the Old City of Jerusalem) and the West Bank," the alert adds.

Asked whether the limitations were directly connected to Iran’s threats, State Department spokesperson Matthew Miller declined to speak to the specific assessments motivating the policy but acknowledged the public warnings from Iran and said Israel is in "a very tough neighborhood."

"Clearly we are monitoring the threat environment in the Middle East and specifically in Israel, and that's what led us to give that warning to our employees and their family members and to make it public so all U.S. citizens who either live in Israel or traveling there are aware of it," he said.

-ABC News' Shannon Crawford

White House National Security Council spokesman John Kirby told ABC's "Good Morning America" Sunday that any response to Iran's Saturday night attack is up to Israeli forces.

But Kirby stressed that President Joe Biden does not want the situation to escalate or have the U.S. drawn further into any conflict.

When asked by ABC News' Whit Johnson about a response from Israel, Kirby said that it is up to the Israeli government to decide how to respond. He added that "the damage was extremely light," and the defenses in place proved Israel can defend itself.

"I won't speak for the Israelis. It's going to be up to them to decide whether and how they'll respond to this," Kirby said. "They showed last night, an incredible military capability on their own, but certainly in concert with friends."

When pressed about reports that Biden told Israeli Prime Minister Benjamin Netanyahu the U.S. would oppose a counterattack on Iran, Kirby said it was "not an accurate reading" of the president's message. He emphasized that the White House does not "want to see the situation escalate further."

"The president understands the prime minister runs a government for a sovereign state of Israel, and that they'll decide whether and how they're going to respond to what Iran did last night," Kirby said.

Kirby reiterated the White House's message that the president will do "whatever he has to protect our troops and our facilities, our people in the region." He said there is no current threat to U.S. service members and facilities, noting that more U.S. forces moved into the region after Oct. 7 to help defend Israel and shipping channels in the Red Sea.

"We're going to obviously be vigilant to any potential threat to our forces in the region," Kirby said. "But the president has been clear we are not looking for a wider war. We're not looking for a second front or a third front. We're not looking to see escalation and we're certainly not looking for a war with Iran."

Kirby added that good intelligence about the attack helped the U.S. and Israel prepare.

"We've been watching as closely as we could the intelligence picture, we had a pretty good indication of the size and the scale and the scope of what Iran was planning," Kirby said. "That is why, because we had a good sense of what they were going to do and with how much, we were able to really help Israel knock down almost everything that Iran threw at them."