The delivery of desperately needed humanitarian assistance supplies for Gaza through the Rafah border crossing is expected to start on Friday, as Israel continues to bombard the blockaded enclave.

Hundreds of trucks full of supplies were still waiting on the Egyptian side of the border Thursday, after U.S. President Joe Biden struck a deal with Egypt and Israel to allow relief into Gaza, under withering bombardment by Israel.

The World Health Organization (WHO) also said it expects the Rafah border crossing from Egypt into the Gaza Strip to be opened for desperately needed aid deliveries on Friday.

"Our trucks are loaded and ready to go. We are working with the Egypt and Palestine Red Crescent Societies to deliver our supplies into Gaza as soon as the Rafah crossing is opened, hopefully, tomorrow," WHO chief Tedros Adhanom Ghebreyesus said in Geneva on Thursday.

The U.N. health agency has five trucks full of supplies in place in Egypt near Gaza, said Teresa Zakaria of the WHO's emergency relief office.

Another 40 tons of supplies are expected to arrive there by next week, Tedros said. Among them are medicines for the chronically ill, as well as materials to treat the wounded and other supplies to care for 300,000 people, including pregnant women, he said.

Emergency Relief Coordinator Mike Ryan also named anesthetics, intravenous drips (IVs), painkillers, wound dressings and supplies for amputations as being en route to the Palestinian enclave.