A convoy of aid trucks carrying the first wartime delivery of fuel from outside the Gaza Strip, crosses from Egypt into the southern Gaza Strip at the Rafah border crossing.

Just hours after receiving the fuel delivery, the UN warned its operations in the territory were facing collapse, with most people soon unable to access drinking water.

"Our entire operation is now on the verge of collapse," said Philippe Lazzarini, head of the UN agency for Palestinian refugees.

"To have fuel for trucks only will not save lives anymore," the UNRWA chief wrote on X, formerly Twitter, saying the fuel shortages had prompted critical shortages of drinking water.

"By the end of today, around 70 percent of the population in Gaza won't have access to clean water," he said of the 2.4 million people living in the tiny territory.

Earlier, Thomas White, the head of UNRWA's Gaza operations, said that supplying fuel for trucks did nothing to address the fuel shortages that were crippling hospitals, sewage facilities and water supplies.

"In Rafah, all 10 water wells have stopped pumping, the only source of water in the city -- why? No fuel," he wrote on X, referring to the city on Gaza's southern tip.

He also said the desalination plant in Khan Yunis, which "supplies drinking water for hundreds of thousands of people" had also ground to a halt due to fuel shortages, along with Rafah's only sewage plant.