Egypt said on Thursday it was directing international aid flights for Gaza to an airport in northern Sinai, though delivery of relief into the Palestinian enclave has so far been hampered by Israeli bombardments around the border.

The Rafah crossing between Sinai and Gaza remained open, the Egyptian foreign ministry said, adding that Egypt had asked Israel to avoid targeting the Palestinian side of the crossing after strikes that prevented normal operations there.

Israel's massive bombardment and imposition of a total siege on the Gaza Strip - after a devastating Hamas attack on Israel - has caused alarm in Egypt, which shares a border with the south of the narrow coastal territory and controls the main exit point for the 2.3-million people living there.

Al Arish airport in northern Sinai, about 45 km from the Gaza border, was preparing to receive three aid flights from Qatar and Jordan, but these would not leave the airport until humanitarian corridors had been established, two Egyptian security sources said.

They said Egypt and Jordan had received assurances from the United States that aid would be delivered to Gaza, without giving details.

Israel, retaliating for a deadly incursion by Hamas gunmen across the border last weekend, said on Thursday there would be no humanitarian break to its siege of Gaza until all hostages seized by the militants were freed.

Egypt, a key mediator between Israel and the Palestinians during periods of unrest in Gaza, has said it is trying to enable the delivery of relief but also signalled that any mass exodus of Gazans south across the border would be unacceptable.

Movement of registered travellers through Rafah, which is subject to tight controls, has been interrupted since Israeli air strikes hit the Palestinian side of the crossing earlier this week.

"From the beginning, we emphasised the continued opening of the Rafah crossing to provide humanitarian aid, and the crossing will remain open until we meet the urgent humanitarian needs of Gaza Strip," Egyptian Foreign Minister Sameh Shoukry said in a press conference with his Lithuanian counterpart.

Since Palestinian Islamist group Hamas took control of Gaza in 2007, Israel and Egypt have imposed a blockade, restricting the passage of people and goods in and out of the territory.

In a phone call with British Prime Minister Rishi Sunak on Thursday, Egyptian President Abdel Fattah al-Sisi stressed the need to guarantee humanitarian services and relief to the Palestinians in Gaza, Sisi's office said in a statement.

Sisi also informed Sunak of Egypt's "continuing efforts to push for the pursuit of calm and utmost restraint to prevent sliding into bloodshed, the price of which will be paid by more innocent people, and whose consequences will extend to the entire region", the statement said.