The World Health Organization (WHO) has warned that there were only 24 hours left before a “true disaster” hit Gaza, with water, electricity and fuel supplies running out.
The UN Health agency warning that Israel had intensified the blockade on the enclave after the deadly attack by the Palestinian group Hamas on October 7.
If help doesn't arrive in time, doctors will have to "prepare death certificates for their patients," WHO Regional Director for the Eastern Mediterranean Ahmed Al-Mandhari said late on Monday.
Lack of water in Gaza under Israel blockade is driving people to drink from contaminated sources and could lead to the spread of diseases, the UN agency for Palestinian refugees (UNRWA) explained.
'Life running out'
"There continues to be no water for the vast majority of the population in Gaza," UNRWA spokesperson Juliette Touma told reporters in New York in a video conference from Amman.
"We're talking about two million people in the Gaza Strip who do not have water and water is running out and water is life. Life is running out of Gaza," said Touma.
"We are very concerned about the spread of waterborne diseases if water continues not to be available in Gaza, because we do know that people are resorting to dirty water sources, including wells," she said.
UNWRA used to provide food assistance to almost 1.2 million people in Gaza, but since October 7, no supplies from the organization or any other UN agency have arrived in the Hamas-controlled enclave, which is completely isolated.
Aid deliveries from multiple agencies and governments have been piling up in Egypt's Sinai Peninsula for the past few days amid mounting appeals to Israel to establish a safe corridor into Gaza.
On Tuesday however, relief convoys which have been waiting for days began heading towards the Rafah border crossing with the besieged Palestinian enclave of Gaza, aid officials say.
During 10 days of artillery bombardments and air strikes, the Israeli military has hit the Palestinian side of the Rafah crossing four times, prompting Egyptian authorities to keep it largely closed.
"We have arrived at the terminal and are now waiting for the next step," said Heba Rashed, who runs the aid group Mersal.
Hundreds more lorries were headed along the coast road for the 40km-journey from the Egyptian city of El Arish to Rafah, other aid officials said.
Deal is near
A Red Crescent official confirmed that aid convoys were being assembled on the Egyptian side of the divided border city of Rafah.
"We've not been told what time we're going to cross but we were asked to head for Rafah," the Egyptian Red Crescent official said, asking not to be identified.
"You could say we're nearing a deal on the entry of aid and the exit of foreigners," said the official, who was himself headed to Rafah.
The Israeli military launched its devastating bombardment after Hamas fighters broke through the heavily fortified border, killing more than 1,400 people.
The reprisals have killed at least 2,750 people in Gaza, according to health officials in the territory. The casualties on both sides have mostly been civilians.