The World Health Organisation (WHO) called on Friday for a humanitarian corridor to be set up in Gaza to allow aid workers to evacuate the wounded and bring in life-saving medicines.
WHO officials have discussed the proposal with both Israeli and Egyptian officials, but there has been no response yet, WHO spokesman Paul Garwood said.
US Secretary of State John Kerry pressed regional proxies to agree on a Gaza ceasefire on Friday as the death toll soared to over 800. At least 4,500 people have been injured, the WHO said.
In a statement, the UN health agency said that it was difficult for the sick and wounded to get access to health care and that some needed to leave the coastal strip for treatment.
Four hospitals have been damaged since July 8 when Israel launched air strikes on Gaza, the WHO said, including al Aqsa hospital, the main hospital for central Gaza which came under direct fire on Monday.
"WHO calls for the creation of a humanitarian corridor for the evacuation of the injured, as well as for the supply of life-saving medicines. The humanitarian corridor should extend to protect the safe passage of patients to access crossing points and exit outside the Gaza Strip for medical care."
A shipment of WHO medical supplies, enough to treat some 400-500 people, was expected to arrive from Amman, Garwood said, noting that nearly 600 people were injured on Thursday alone.
"People are dying at an alarming rate, being injured at a very alarming rate," Jens Laerke of the UN Office for the Coordination of Humanitarian Affairs (OCHA) said.
"We are calling for these localised ceasefires whereby the wounded can be evacuated and we can access people with both health care and other kinds of relief."