The United Nations children's fund said Thursday that Israel had agreed to restore power to a key desalination plant in southern Gaza, which could provide much-needed water to a million displaced people.

"UNICEF confirms an agreement (with Israel) was reached to re-establish the medium voltage feeder power line for the Southern Gaza Desalination Plant," said Jonathan Crickx, the agency's spokesman in the Palestinian territories.

Water has become scarce for the Palestinian territory's 2.4 million residents since war broke out nearly nine months ago.

More than two thirds of Gaza's sanitation and water facilities have been destroyed or damaged, according to data cited by UN agencies, and only an intermittent supply of bottled water has been allowed in since Israel imposed a punishing siege on the territory.

The plant in Khan Yunis, once resupplied with electricity, should produce enough water to "meet what humanitarian standards define as a minimum intake of 15 litres per day of drinking water per person, for nearly a million displaced people" in southern Gaza, Crickx said.

"This is an important milestone, and we are very much looking forward to seeing it implemented."

Israel's coordinator for civilian affairs in the Palestinian territories, known as COGAT, did not immediately respond to an AFP request for comment.

The plant should be able to produce 15,000 cubic metres, or 15 million litres, of water per day at full capacity, according to UNICEF.

After Hamas's unprecedented attack on October 7, Israeli Defence Minister Yoav Gallant announced that he was imposing "a complete siege" on Gaza with "no electricity, no water, no gas".

Since then, the humanitarian situation has deteriorated considerably, according to aid groups working in Gaza.

Crickx said it was vital to also see "generators and infrastructure to be delivered" to address the damage to the war-battered territory, adding more than 60 percent of its water distribution systems have been damaged since October.

The Gaza war started with Hamas's attack on southern Israel that resulted in the deaths of 1,195 people, mostly civilians, according to an AFP tally based on Israeli official figures.

Israel's military campaign in Gaza has killed at least 37,765 people, also mostly civilians, according to data provided by the health ministry in the Hamas-run territory.