Egypt’s Foreign Minister Sameh Shoukry blamed Israel, saying that it had not “taken a stance that enables opening the crossing from Gaza’s side to let aid in, or to let third-country nationals out.” Israeli media, meanwhile, reported that “American demands on the humanitarian issue” were delaying a deal.

The standoff over the Egyptian border has deepened frustration and panic among aid groups, who warn that time is running out for wounded and displaced Gazans to receive critical — and in many cases, lifesaving — supplies, as the humanitarian situation rapidly deteriorates.

The crisis in Gaza was sparked by a surprise Hamas incursion into Israel on Oct. 7, killing more than 1,400 people across towns and military bases, and taking more than 200 Israeli and foreign nationals back to Gaza as hostages.

In response, Israel’s army has launched its own searing assault on Gaza, a territory that has lived under Hamas rule for 17 years and an Israeli blockade for 16, killing at least 2,750 people and wounding almost 10,000 as body bags run out and the dead are now buried in mass graves.

More than 2 million people live in the cramped enclave less than half the size of New York City, with closed border crossings and no safe space as the bombs rain down. Israeli officials have declared the area under “full siege”, meaning that no fuel, food or lifesaving medical supplies are allowed to enter.

To keep the lights on in Gaza City’s largest hospital, Wissam AbuJarad, an anaesthetist, said, staff were collecting gas from dwindling stocks in the area to maintain a steady supply to their generators.

“If we run out of fuel, then we will lose all of the patients in the ICU, the babies in the incubators and the patients who need surgery,” AbuJarad said.

The medic had not seen his wife and children, who had moved four times already in search of safety, since the war began. He said that some staff had been reduced to drinking from IV solution bags, because Israel had cut off water supplies to the enclave.

“If this is how the situation is for medical staff, how do other people manage,” he asked.

Israel says that its military campaign is aimed at ending Hamas rule in Gaza forever, and in daily statements, it has listed leadership figures targeted, as well as alleged military facilities that its warplanes have struck.

The army also said Monday that 1,400 missiles have been launched from Gaza toward the city of Ashkelon, most of them intercepted by the Iron Dome air defense system. One person has been killed.

Blinken arrived back in Israel Monday to pledge support to Netanyahu’s government as it prepares to intensify its military offensive. Israeli troops were massed along its border ahead of a possible ground incursion, and have warned more than 1 million Gazans to retreat to the enclave’s south, to escape the worst of the coming storm.

During a whirlwind set of meetings with Arab leaders including Egyptian President Abdel Fatah El-Sisi, Saudi Crown Prince Mohammed bin Salman, Palestinian Authority President Mahmoud Abbas and King Abdullah II of Jordan, regional officials have made it clear to Blinken that they oppose the displacement of Palestinians outside of Gaza into Egypt, fearing that they may never be able to return.

Following his meeting with Sisi, Blinken said Rafah “will be opened” so that hundreds of U.S. citizens could have the chance to leave, and that the United States was in talks with the United Nations, Egypt, Israel and others to agree on a mechanism to allow aid into Gaza.

There is a team of U.S. diplomats trying to access the border but the closest they have been able to get is the city of Ismailiyya, 150 miles to the west, due to apparent security issues.

“We have been trying,” said a State Department official, speaking on condition of anonymity to discuss a sensitive diplomatic matter. “The Egyptians have told us there are acute security threats there that prevent it.”

Egypt believed a deal had been reached with the United States and Israel to open the crossing for almost five hours, to allow 100 trucks carrying humanitarian aid into Gaza and foreign passport holders to leave the strip, according to a source with knowledge of Egyptian diplomatic efforts, who spoke on the condition of anonymity to discuss sensitive negotiations.

When asked what had happened with efforts to reopen the crossing, a spokesman for the U.S. Embassy in Cairo on Monday referred back to a comment from Blinken on Sunday in which he blamed Hamas for preventing foreign nationals from leaving Gaza.

The Washington Post reported over the weekend, however, that Israel had been unwilling to commit to not striking aid vehicles that enter Gaza. Officials were discussing the possibility of setting up a screening system that would allow the Israelis to inspect goods in each vehicle entering Gaza.

But such a condition “will be impossible on the ground,” the source with knowledge of Egyptian diplomatic efforts said. How inspections of aid will work is “the main concern” holding up a deal.

Jens Laerke, spokesman for the United Nations Office for the Coordination of Humanitarian Affairs in Geneva, said Monday that the agreement was not, “as of this point, a done deal.”

Several hundred people gathered on the Palestinian side of the gate on Monday in anticipation of the border reopening, television footage from the crossing showed. Palestinians who have been waiting for days on the Egyptian side of the border to cross back to their families in Gaza piled into buses on Monday to wait, according to Ahmed Salem, head of the Sinai Foundation for Human Rights, which has a team monitoring the border.

But Wael Abu Omar, the Palestinian spokesman for the Rafah crossing, said the Palestinian side had not received any official notice from the Egyptians that the border would reopen Monday, so no Palestinian crews were manning the crossing as of midmorning.

Like the rest of the 25-mile long enclave, Rafah has been subject to Israeli airstrikes. The crossing itself was damaged last Tuesday, leading to its closure. In the town of Rafah, close to the crossing, civilians have also been killed. One resident, Mohamed Youssef Abutaha, described through tears how he had been stocking up on groceries with his son and his sister Monday morning when an Israeli airstrike slammed into the street up ahead of them. “It fell in the sand,” he said. “If it had hit the building, we would instantly have died.”

The U.N. Office for the Coordination of Humanitarian Affairs said Sunday that nearly 600,000 Gazans have been displaced by the fighting — more than a quarter of the population.

“Dying under bombs in Gaza cannot be the only option left to people. Hospitals are overwhelmed. There are no more painkillers. Our staff tell us about wounded people screaming in pain, and people who can’t get to the hospital,” said Claire Magone, the general director of Doctors Without Borders’ French chapter.

The newly appointed U.S. envoy for humanitarian efforts, David Satterfield, a former ambassador to Lebanon and Turkey, will be in charge of helping establish “safe zones” inside Gaza, U.S. officials said. But the practicalities remain elusive, and aid groups have warned that forced displacement without guarantees of safe passage or return would amount to a war crime.

Fighting has also flared along Israel’s borders with Lebanon and Syria, raising the prospect that the conflict could still drag in more regional players.

The Israel Defense Forces and Defense Ministry said in a statement Monday they plan to evacuate Israelis from 28 communities just over a mile from the country’s border with Lebanon. They will be considered internally displaced and housed in state-funded accommodation.

The IDF said earlier it struck Hezbollah military infrastructure in Lebanon overnight in retaliation for the Iranian-backed militant group’s attack on Israeli territory Sunday. Hezbollah, the Lebanese militant group, said it conducted the strike with guided missiles in response to Israeli attacks, including the shelling that killed a Reuters videographer and injured six other journalists, all of them clearly identifiable in protective gear marked “PRESS” in southern Lebanon on Friday.

On Monday, Hezbollah released a video showing its snipers shooting at Israeli surveillance cameras at several points along the border, destroying them.

Loveluck reported from London, Hudson from Jerusalem and Mahfouz from Cairo. Hazem Balousha in Gaza, Noga Tarnopolsky in Jerusalem, Karen DeYoung in Washington and Leo Sands in London contributed to this report.