WASHINGTON, United States - The head of the United Nations agency for Palestinian refugees has accused Israel of laying the groundwork for the mass expulsion of Gazans into Egypt, an accusation Israel said was "simply not true".

More than two months of deadly war between Israel and Hamas, sparked by the militant group's October 7 attacks, have displaced most of Gaza's population, but Palestinians are largely barred from leaving the narrow besieged territory.

In an opinion piece published on Saturday in the Los Angeles Times, UNRWA chief Philippe Lazzarini pointed to the worsening humanitarian crisis in Gaza and the increasing concentration near the border of displaced civilians who fled the fighting, first in the north and then further south.

"The United Nations and several member states, including the US, have firmly rejected forcibly displacing Gazans out of the Gaza Strip," Lazzarini said.

"But the developments we are witnessing point to attempts to move Palestinians into Egypt, regardless of whether they stay there or are resettled elsewhere."

The widespread destruction in the Palestinian territory's north and the resulting displacements were "the first stage of such a scenario", he added, while forcing civilians from the southern city of Khan Yunis closer to the Egyptian border was the next.

"If this path continues, leading to what many are already calling a second Nakba, Gaza will not be a land for Palestinians anymore," Lazzarini said, using the Arabic term for the exodus or forced displacement of 760,000 Palestinians during the war that coincided with Israel's creation in 1948.

Responding to the accusation, a spokesperson for the Israeli defence ministry office responsible for Palestinian civilian affairs said: "There is not, never was and never will be an Israeli plan to move the residents of Gaza to Egypt. This is simply not true."

- 'Voluntary resettlement' -

Israeli Intelligence Minister Gila Gamliel said last month that one "option" after the war would be "to promote the voluntary resettlement of Palestinians in Gaza, for humanitarian reasons, outside of the Strip".

And former Israeli officials have suggested in TV interviews that Egypt could build vast tent cities in its Sinai desert, with international funding.

A small number of Gazans have been allowed to cross into Egypt for medical treatment, and some foreign nationals trapped in the territory at the outset of the war were also allowed to evacuate by way of the Rafah crossing -- Gaza's only border post not under Israeli control.

But other Palestinians are currently blocked from leaving, with the territory's estimated 1.9 million displaced people -- out of a total population of 2.4 million -- turning the border town of Rafah into a vast camp.

The war in the Gaza Strip was triggered by Hamas's bloody October 7 attack on Israel, which left 1,200 people dead and saw another 240 taken hostage, Israeli officials say.

The country vowed to eliminate Hamas in response, and its ensuing military campaign has killed at least 17,700 people, according to Gaza's Hamas-run health ministry.

Aid groups have sounded the alarm on the "apocalyptic" humanitarian situation in the narrow territory, warning it is close to being overwhelmed by disease and starvation.