Egypt is facing mounting pressure to act as neighboring Gaza gets pummeled by Israeli strikes after last weekend's brutal assault on Israel by Hamas.

In the wake of the Hamas attacks, Israel closed its two border crossings with Gaza and imposed a "complete siege" on the territory, blocking supplies of fuel, electricity and water.

That has left the Rafah crossing between Gaza and Egypt as the only viable outlet to get people out of the enclave and supplies into it.

But the crossing has been closed for much of the past week, with neither Gazans nor foreign nationals able to cross, and tons of vital humanitarian supplies for people in Gaza piling up on the Egyptian side of the border.

A Palestinian border official told CNN that Egypt had blocked the gates of the crossing with concrete slabs. Egypt has denied reports that it has closed its side of the crossing, and said the Palestinian side had been damaged by repeated Israeli airstrikes.

Egyptian Foreign Minister Sameh Shoukry told CNN on Saturday that the crossing was open but aerial bombardment had rendered the roads "inoperable" on the Gaza side.

The Biden administration has held talks with Israel and Egypt about ensuring safe passage for Americans and other civilians out of Gaza.

But Egypt, which already hosts millions of refugees, is uneasy about the prospect of hundreds of thousands of Palestinians crossing into its territory. More than two million Palestinians live in Gaza, a densely packed coastal enclave that is under intense Israeli bombardment.

Israel's military has called for the 1.1 million residents of northern Gaza to evacuate their homes and move southwards, according to the United Nations, as Israel amassed 300,000 reservists on the border in apparent preparation for a ground incursion.

Hamas' brutal October 7 attack on Israel killed 1,300 people, prompting retaliation by Israel against which has killed 2,329 people in Gaza. As attacks intensify and Israel continues to cut off essential supplies, rights groups have raised concerns about a potential humanitarian catastrophe.

People and supplies stuck at the border

Movement through the Rafah crossing is normally extremely limited; only Gazans with permits as well as foreign nationals are able to use it to travel between Gaza and Egypt. But the border has been effectively sealed shut in recent days.

Western efforts to reopen the crossing and evacuate their nationals from Gaza continued over the weekend, with the US advising Americans in the strip to move closer to Rafah in case the crossing opened, if it was possible for them to relocate safely.

Meanwhile, hundreds of Palestinians with foreign passports have flocked to the border but have been left sitting in the streets for hours, the Palestinian border official said Saturday.

"Unfortunately, the crossing is closed. There is no crossing for any traveler or any holder of Arab or foreign residency or otherwise," the official told CNN.

Egyptian officials were not allowing US and other foreign nationals to enter Egypt through the Rafah border crossing because a deal had not been struck on facilitating aid into the strip, Egyptian sources told government-linked Alqahera News on Saturday, which is linked to the government.

Meanwhile, humanitarian supplies are continuing to arrive in Egypt as diplomatic efforts continue to bring aid to Palestinians in Gaza.

Aid flights from Jordan, Turkey, the United Arab Emirates, the World Health Organization, and the Red Cross have arrived in the Egyptian city of El-Arish, approximately 45 kilometers (23 miles) away from Rafah, according to footage aired on Egyptian state television on Saturday.

The Red Crescent has warehouses full of humanitarian aid and the El-Arish stadium has been prepared to accommodate more aid, an Egyptian Red Crescent official said on Saturday.

A World Health Organization plane carrying medical supplies landed in Egypt on Saturday, said Tedros Ghebreyesus, director-general of WHO. However, the organization is still waiting for humanitarian access through the crossing.

Shoukry said Egypt has tried to ship humanitarian aid to Gaza but has not received the proper authorization to do so.

Egypt said Sunday it would intensify its efforts to try and help relief organizations deliver aid to Gaza as the territory's humanitarian crisis worsens, though a statement from the Egyptian presidency said "national security is a red line and that there is no compromise in its protection."

'We sympathize'

Speaking at a military graduation ceremony Thursday, Egyptian President Abdel Fattah el-Sisi compared the situation in his country to a lone house in a neighborhood that's on fire. He said that rumors about Egypt not seeking to help its Palestinian neighbors are untrue.

"We are making sure that aid, whether medical or humanitarian, at this difficult time, makes it to the strip," Sisi said, adding that "we sympathize."

But he warned that Egypt's ability to help has limits.

"Of course we sympathize. But be careful, while we sympathize, we must always be using our minds in order to reach peace and safety in a manner that doesn't cost us much," he said, adding that Egypt hosts 9 million migrants already. The largest groups in the country's migrant population are from Sudan, Syria, Yemen and Libya, according to a 2022 report by the UN's International Organization for Migration.

Egypt's foreign ministry warned Friday against Israel's call for evacuation, calling it "a grave violation of international humanitarian law" that would put the lives of more than 1 million Palestinians in danger.

The Jordanian official told CNN Thursday that Jordanian and Egyptian officials are applying "diplomatic and political pressure on the Israeli government to allow for the safe passage of aid into Gaza through the Rafah crossing."

But Egyptian media outlets have sounded alarms about the prospect of allowing Palestinian refugees into the country, warning that it may forcefully displace Gazans into Sinai.

Sisi echoed those sentiments on Thursday. "There is a danger" when it comes to Gaza, he said -- "a danger so big because it means an end to this (Palestinian) cause... It is important that (Gaza's) people remain standing and on their land."

Jordan's King Abdullah, who met with Blinken Friday, warned against "any attempt to displace Palestinians from any Palestinian territories or to cause their displacement."

The vast majority of Gaza's residents today are Palestinian refugees from areas that fell under Israeli control in the 1948 Arab-Israeli war. That war marked Israel's creation, but it is also lamented by Palestinians as the Nakba, or "catastrophe," as more than 700,000 Palestinians were either expelled or forced to flee their homes in what is now Israel.

Tens of thousands of Palestinians took refuge in Gaza, which fell under Egyptian control after the war. Israel captured the territory from Egypt in the 1967 war and began settling Jews there, but it withdrew its troops and settlements in 2005.

Additional reporting by CNN's Celine Alkhaldi, Caroline Faraj, Hamdi Alkhshali, Mitchell McCluskey, Magdy Samaan and Lauren Kent