The UN rights chief voiced deepened concerns Wednesday that Israel's plans to expand its offensive in Gaza aim to create conditions threatening Palestinians' "continued existence" in the territory.

Israel's military has called up tens of thousands of reservists for an expanded offensive in the Gaza Strip, which an official said would entail the "conquest" of the Palestinian territory.

"Israel's reported plans to forcibly transfer Gaza's population to a small area in the south of the Strip and threats by Israeli officials to deport Palestinians outside of Gaza further aggravate concerns that Israel's actions are aimed at inflicting on Palestinians conditions of life increasingly incompatible with their continued existence in Gaza as a group," Volker Turk, the United Nations High Commissioner for Human Rights, said in a statement.

"There is no reason to believe that doubling down on military strategies, which, for a year and eight months, have not led to a durable resolution, including the release of all hostages, will now succeed," he said.

"Instead, expanding the offensive on Gaza will almost certainly cause further mass displacement, more deaths and injuries of innocent civilians, and the destruction of Gaza's little remaining infrastructure."

Nearly all of the Palestinian territory's 2.4 million people have been displaced at least once during the war, sparked by Hamas's October 7, 2023 attack on Israel.

A more than two-month Israeli blockade on all aid into Gaza has worsened the humanitarian crisis.

According to AFP, Turk warned that stepping up the Israeli offensive "would only compound the misery and suffering inflicted by the complete blockade on the entry of basic goods for almost nine weeks now".

"Gaza's residents have already been deprived of all lifesaving necessities, particularly food, with relentless Israeli attacks on community kitchens and those trying to maintain a minimum of law and order," he said.

"Any use of starvation of the civilian population as a method of war constitutes a war crime," Turk said, adding that "the only lasting solution to this crisis lies through full compliance with international law".

The health ministry in Hamas-run Gaza says at least 2,507 people had been killed since Israel resumed its campaign in mid-March, bringing the overall death toll from the war to 52,615.