House Republican Conference Chairwoman Elise Stefanik of New York will be giving remarks in the Israeli Knesset on Sunday, according to her office. Stefanik will be the highest-ranking member of the House to visit Israel following the Oct. 7 attack.

Stefanik plans to slam President Joe Biden for recently halting some military aid to Israel, according to excerpts of her speech reviewed by ABC News.

"I have been clear at home, and I will be clear here: There is no excuse for an American president to block aid to Israel," Stefanik will say during the address.

Biden announced the U.S. would withhold certain bomb deliveries to Israel over fear they could be used in Rafah, but the Biden administration informed Congress it's moving forward with more than $1 billion in new arms agreements with Israel.

The congresswoman will address the rise in antisemitism in the U.S., House Republicans' support for Israel and even mention her close ally, former President Donald Trump.

"I have been a leading proponent and partner to President Trump in his historic support for Israeli independence and security," Stefanik will say.

-ABC News' Lauren Peller

Three U.S. medical professionals remain in Gaza despite warnings from the U.S. State Department that the American government may not be able to get them out later.

Tamer Hassan, a registered nurse, Dr. Jomana Al-Hinti and Dr. Adam Hamawy were the only ones out of a group of 20 American medical professionals who stayed behind to help treat patients.

"They understand that the U.S. embassy may not be able to facilitate their departure in the same manner as we have just effected today," a person with knowledge of the situation told ABC News.

Hamawy released a statement Saturday explaining why he stayed behind.

"We worry that the European Hospital we currently are in will suffer a similar fate of Al-Shifa and Nasser hospitals, where humanitarian workers, patients, and civilians were massacred," he said.

"To my wife, daughters and son, I know it hurts that I am not coming home this weekend, and I am sorry. But I know that you are proud that I am upholding my oath to never leave anyone behind," he added.

The doctors who left Gaza "made their way to safety with assistance from the U.S. Embassy in Jerusalem," a State Department spokesman said.

-ABC News' Anne Flaherty, Nadine Shubailat and Zoe Magee

Israeli cabinet minister Benny Gantz has given Israeli Prime Minister Benjamin Netanyahu an ultimatum: approve a post-war plan by June 8, or he will resign, Gantz said at a press conference.

"While the Israeli soldiers show supreme bravery on the front, some of the men who sent them into battle behave with cowardice and irresponsibility," Gantz said.

A leader of the National Unity Party and a minister in the war cabinet, Gantz's resignation would not necessarily trigger the collapse of the government on its own, but would be politically significant.

The ultimatum come on the heels of a speech by defense minister Yoav Gallant, who is demanding a plan for the "day after" the war.

-ABC News' Jordana Miller and Dana Savir

Israel announced that it has identified the body of a fourth hostage this week. Ron Benjamin, 53, was killed during the Oct. 7 Hamas attack and taken into Gaza, according to the Israel Defense Forces.

The bodies of three other hostages were also recovered in a tunnel in the same operation, according to the IDF.

Benjamin was a family man who loved cycling, the Hostages Families Forum said in a statement.

"He used to go out for a ride every Saturday, just as he did on that fateful Saturday when he was taken hostage from the Kibbutz Be’eri area while on a cycling trip," the statement said.

-ABC News' Victoria Beaule

National security adviser Jake Sullivan stressed the U.S. is working "urgently and relentlessly" to get a hostage deal in place, but did not have any major progress to share Monday.

Sullivan noted that he met with the families of American hostages this past Friday, and that "they know how hard the president is working on this."

On where the hostage negotiations stand currently, Sullivan turned to the architect of the Good Friday agreement in Ireland.

"Sen. [George] Mitchell said quite famously, "'Negotiations are 1,000 days of failure and one day of success.' And right now, we're in the former days rather than the latter day," he said.

"[T]here could be a cease-fire tomorrow if Hamas simply released women, wounded and elderly hostages, all innocents. Israel put a forward-leaning proposal on the table for a cease-fire and hostage deal. The world should be calling on Hamas to come back to the table and accept a deal," Sullivan said.

-ABC News' Molly Nagle