Israel vowed Thursday to "intensify" its ground offensive in Rafah, in defiance of global warnings over the fate of hundreds of thousands of Palestinian civilians sheltering in Gaza's far-southern city.
Defence minister Yoav Gallant said "additional forces will enter" the Rafah area and "this activity will intensify".
"Hundreds of targets have already been struck and our forces are manoeuvring in the area," Gallant said following a troop visit on Wednesday.
Israel's top ally the United States has joined other major powers in appealing for it to hold back from a full ground offensive against Hamas in Rafah, the last city in Gaza so far spared heavy urban fighting.
But Prime Minister Benjamin Netanyahu insisted Thursday that the ground assault on Rafah was a "critical" part of the army's mission to destroy Hamas and prevent any repetition of the 7 October attack that triggered the war.
"The battle in Rafah is critical... It's not just the rest of their battalions, it's also like an oxygen line for them for escape and resupply," he said.
Many of those fleeing Rafah have headed for the coastal area of Al-Mawasi that Israel has declared a "humanitarian zone". Satellite images also show a vast new tent city that has sprung up near the main southern city of Khan Yunis.
Many of the displaced are "exhausted, they are scared, they don't have resources", said Javed Ali, head of emergency response in Gaza for International Medical Corps.
Ali, who works at a field hospital in Al-Mawasi and is an aid veteran of multiple war zones, said the situation in Gaza was "far more catastrophic" than anything he had seen before.
"The immense number of trauma cases, the lack of resources, the interrupted supply chain... it's something that I've never seen."
More than seven months into the conflict, Israeli forces were also fighting Palestinian militants in new flashpoints in northern and central Gaza.
Heavy battles rocked the Jabalia refugee camp where Israel lost five soldiers to friendly fire on Wednesday.
In comments to troops outside Rafah Thursday, army chief Herzi Halevi pledged: "We won't let Hamas rebuild itself and they will pay a price."
Washington has repeatedly urged its ally to take greater steps to protect civilians -- and to make a post-war plan for Gaza to avoid being mired in a long counterinsurgency campaign.
Netanyahu insisted Wednesday that any planning for post-war Gaza was "empty talk" until Hamas is defeated.
In signs of a growing rift inside the war cabinet, Gallant called on Netanyahu to "declare that Israel will not establish civilian control over the Gaza Strip".
"The 'day after Hamas' will only be achieved with Palestinian entities taking control of Gaza, accompanied by international actors, establishing a governing alternative to Hamas rule," Gallant said.
Hamas chief Ismail Haniyeh insisted the movement is "here to stay".
Palestinian president Mahmud Abbas told an Arab League summit in Bahrain that Hamas's "unilateral decision" to launch the October 7 attack had "provided Israel with more pretexts and justifications to attack the Gaza Strip".
Hamas expressed "regret" at the president's criticism.
In a statement issued after the summit, the Arab League demanded an "immediate and permanent ceasefire in Gaza".
The 22-member bloc also called for UN peacekeepers to be deployed in the occupied Palestinian territories until a two-state solution has been implemented.
The war broke out after the October 7 attack on southern Israel which resulted in the deaths of more than 1,170 people, mostly civilians, according to an AFP tally of Israeli official figures.
The militants also seized about 250 hostages, 128 of whom Israel estimates remain in Gaza, including 38 the military says are dead.
Israel's devastating military retaliation has killed at least 35,272 people, mostly civilians, according to the health ministry in Hamas-ruled Gaza.
An Israeli siege on Gaza has brought dire shortages of food as well as safe water, medicines and fuel for its 2.4 million people. The threat of famine hangs over parts of the war-ravaged territory.
The arrival of occasional aid convoys has slowed to a trickle since Israeli forces took control last week of the Gaza side of the Rafah crossing.
The US military said Thursday it had completed a temporary pier on Gaza's coast, part of a project to ship in relief supplies from the Mediterranean island of Cyprus.
US Central Command said it expected around 500 tonnes of aid to be delivered on board several ships over the coming days.
But Farhan Haq, a spokesman for UN chief Antonio Guterres, said negotiations were still ongoing on how the aid would be distributed after Washington ruled out any involvement by its troops.
Haq also reiterated the UN's preference for a land route, saying "getting aid to people in need into and across Gaza cannot and should not depend on a floating dock far from where needs are most acute".
In a case before the International Court of Justice in The Hague, South Africa accused Israel on Thursday of stepping up what it called a "genocide" in Gaza, urging the court to order a halt to Israel's assault on Rafah.
"As the primary humanitarian hub for humanitarian assistance in Gaza, if Rafah falls, so too does Gaza," said South Africa in its submission.
"In attacking Rafah, Israel is attacking the 'last refuge' in Gaza, and the only remaining area of the Strip which has not yet been substantially destroyed by Israel," the document added.
Israel, which is due to respond on Friday, has described South Africa's case as unfounded.