Mediators in Cairo were pushing on Tuesday for an agreement to stop the war in the Gaza Strip as international concern mounted over Israel’s plan to press its ground offensive into the southern city of Rafah, where nearly half of the territory’s population has sought refuge.
President Biden sent the C.I.A. director, William J. Burns, to join the talks, and said that he had spoken with Prime Minister Benjamin Netanyahu of Israel and the leaders of Egypt and Qatar to “push this forward” over the past month.
The negotiations came as the United Nations, the United States and other countries have expressed increasing alarm about the prospect of an Israeli incursion into Rafah, where about 1.4 million people are sheltering, many in tents, without adequate food, water and medicine.
Mr. Netanyahu has ordered the military to draw up plans to evacuate civilians from the city, but many Palestinians say that no place in the territory is safe. Mr. Biden has said that the United States opposes an Israeli invasion of the city without a “credible plan” to protect civilians from harm. Egypt has said it will not let refugees cross the border into Sinai.
Negotiators in Cairo, Mr. Biden said, were hoping to hammer out an agreement between Israel and Hamas that would free the remaining hostages in Gaza and halt the fighting for at least six weeks. Mr. Burns was meeting with the head of Mossad, Israel’s intelligence agency, the prime minister of Qatar and Egyptian officials, according to Al Qahera, an Egyptian state-owned television channel.
John F. Kirby, a National Security Council spokesman, said on Tuesday that the talks were “moving in the right direction” but declined to provide details. Israel and Hamas, however, remain far apart in their publicly stated positions and have shown no signs of budging. Israel, for one, has said it will not stop fighting in Gaza until Hamas is crushed and the hostages are freed.
“Nothing is done until it is all done,” Mr. Kirby told reporters at the White House.
Asked about whether the United States believes that the American hostages in Gaza are still alive, he said, “We don’t have any information to the contrary.”
The expected Israeli advance into Rafah has led to mounting pressure on Egypt, which controls a major border crossing into the city.
Rather than opening its border to give Palestinians a refuge from the expected onslaught, Egypt has reinforced its frontier with Gaza.
There have been fears that any Israeli military action that sends Gazans spilling into Egyptian territory could jeopardize the decades-old peace treaty between Israel and Egypt, an anchor of stability in the Middle East. But on Monday, Egypt offered assurances that the treaty would stand.
Mr. Netanyahu has described Rafah as Hamas’s last stronghold. On Monday, after Israeli forces freed two hostages held in the city in a nighttime commando operation, he said that “only continued military pressure, until total victory, will bring about the release of all of our hostages.”
But the rescue operation coincided with a wave of Israeli strikes that killed dozens in Rafah, Gazan health authorities said, pointing to the risks to civilians of a full-scale invasion of the city.
Officials of the United Nations and the International Criminal Court have warned of catastrophic consequences if Israeli forces were to invade the city.
Stéphane Dujarric, a spokesman for the U.N. secretary general, António Guterres, said that an incursion into Rafah would jeopardize the delivery of essential aid through the city’s border crossing with Egypt.
The United Nations, he indicated, would play no part in Israel’s evacuation plans.
“We will not be party to forced displacement of people,” Mr. Dujarric said. “As it is, there is no place that is currently safe in Gaza.”
Karim Khan, the chief prosecutor of the International Criminal Court, said that he was “deeply concerned” about a full-scale ground offensive in Rafah, and hinted at the possibility of prosecution for war crimes.
“All wars have rules and the laws applicable to armed conflict cannot be interpreted so as to render them hollow or devoid of meaning,” he said in a statement posted on social media.