Israel-Gaza updates: IDF says 2 hostages rescued from Gaza

The United Nations International Children's Emergency Fund on Friday urged Israel and Hamas to refrain from escalating fighting in Rafah, the southernmost governorate in the war-torn Gaza Strip, where more than a million people have sought refuge after being displaced from their homes.

"UNICEF is urgently calling on the parties to refrain from military escalation in Rafah Governorate in Gaza where over 600,000 children and their families have been displaced -- many of them more than once," UNICEF Executive Director Catherine Russell said in a statement. "An escalation of the fighting in Rafah, which is already straining under the extraordinary number of people who have been displaced from other parts of Gaza, will mark another devastating turn in a war that has reportedly killed over 27,000 people -- most of them women and children."

"Thousands more could die in the violence or by lack of essential services, and further disruption of humanitarian assistance," she added. "We need Gaza's last remaining hospitals, shelters, markets and water systems to stay functional. Without them, hunger and disease will skyrocket, taking more child lives."

ABC News' Nasser Atta, Edward Szekeres and Morgan Winsor

The U.S. would not support Israel sending its military into the southern Gaza city of Rafah -- where many Gaza residents have fled for safety -- if Israel does not consider the impact to civilians, White House national security spokesperson John Kirby told reporters.

"More than a million Palestinians are sheltering in and around Rafah. That's where they were told to go," Kirby said. "The Israeli military has a special obligation, as they conduct operations there or anywhere else, to make sure that they're factoring in protection for civilian life -- particularly civilians that were pushed into southern Gaza by operations further north."

"Given the circumstances and the conditions there that we see right now, we think a military operation at this time would be a disaster for those people," Kirby said.

Kirby noted that the U.S. has not seen any Israeli plans "that would convince us that they are about to or imminently going to conduct any kind of major operations in Rafah."

-ABC News’ Fritz Farrow

State Department deputy spokesperson Vedant Patel acknowledged Thursday that the U.S. was aware of reports that two American citizens had been detained by the Israel Defense Forces in Gaza but said he couldn’t share anything more.

"We have no higher priority than the safety and security of American citizens overseas," Patel said. "We are aware of these reports, and we are currently seeking additional information. But I don't have any additional information to share and would not be able to at this point, given the privacy considerations."

White House national security spokesperson John Kirby told reporters, "Obviously, this is the kind of thing to take very seriously. So, we'll be talking to our Israeli counterparts and trying to get information, more context here, about what happened."

-ABC News’ Shannon Crawford

Israeli Prime Minister Benjamin Netanyahu will likely send negotiators to Cairo in the coming days, an Israeli political source told ABC News.

Egypt and Qatar are co-hosting a new round of negotiations on the proposed hostage and cease-fire deal on Thursday in Cairo, according to Egyptian state TV.

-ABC News' Jordana Miller