Palestinians in war-torn Gaza on Thursday awaited the arrival of emergency aid promised in a deal struck by US President Joe Biden, as Israel's military kept up its bombardment of targets in the Hamas-run enclave.

Cargo planes delivered stocks including food and medicine, water purifiers and hygiene products to Egypt's El Arish airport, awaiting the opening of the Rafah border crossing to Gaza.

Egyptian state-linked broadcaster Al Qahera News said the crossing – the only one into and out of the besieged enclave not controlled by Israel – would open on Friday.

On a visit to Cairo, UN Secretary-General Antonio Guterres said there needed to be "rapid, unimpeded humanitarian access" after dire warnings about the impact of the sustained Israeli blockade.

"We need food, water, medicine and fuel now. We need it at scale and we need it to be sustained, it is not one small operation that is required," he added.

In Geneva, the emergencies director of the World Health Organization (WHO), Dr Michael Ryan, said aid needed to get in "every day," calling the deal struck by Biden with Israel and Egypt to allow in 20 trucks "a drop in the ocean of need right now."

"It shouldn't be 20 trucks: it should be 2,000 trucks," he said.

Gaza has been hit by a relentless barrage of Israeli fire in retaliation for a Hamas militant attack on October 7, which Israel said killed at least 1,400 people, most of them civilians.

Some 1,500 Islamist fighters were killed in clashes before the army regained control, the Israeli military said.

Israeli bombing in turn has killed at least 3,785 Palestinians, most of them civilians, according to the Gaza health ministry.

Entire city blocks have been levelled, displacing more than one million of the 2.4 million population, the UN has said.

"The pace of death, of suffering, of destruction... cannot be exaggerated," said UN humanitarian chief Martin Griffiths.

There are fears of worse to come if Israel launches an expected ground invasion to destroy Hamas and rescue more than 200 Israeli and foreign hostages. (AFP)