Israel's defense minister has said its forces are tightening the siege around Gaza City by extending its control of a military corridor across the territory towards the coast.
Isael Katz also issued a final warning to the hundreds of thousands of Palestinians in the city to evacuate southwards, saying those who remained during the offensive against Hamas would be terrorists and supporters of terror.
Hospitals reported that 45 people had been killed by Israeli fire in Gaza City on Wednesday, while the International Committee of the Red Cross (ICRC) said it had been forced to suspend operations there.
Israel is stepping up the assault as Hamas weighs its response to US President Donald Trump's new plan to end the war.
Arab and Turkish mediators are understood to be pressing for a positive response, but a senior Hamas figure has said the group is likely to reject it.
The IDF has described Gaza City as Hamas's last stronghold and said the offensive aims to secure the release of the 48 hostages still held by Hamas - 20 of whom are believed to be alive - and ensure the Palestinian armed group's decisive defeat.
Israel's defense minister told Israeli media that the IDF was currently completing the capture of the Netzarim corridor to the western coast of Gaza - a reference to the Israeli military zone which runs east-west from the perimeter with Israel.
This will tighten the siege around Gaza City, and anyone leaving it south will be forced to pass through the IDF's checkpoints, the Haaretz newspaper quoted Katz as saying.
He warned that this was the last chance for Gaza [City] residents who are interested in moving south and leaving Hamas terrorists isolated in Gaza City itself in the face of IDF activity that continues at full strength.
Those who remain in Gaza will be terrorists and terror supporters, he warned.
The ICRC stated that under international humanitarian law, civilians must be protected whether they stay or leave Gaza City.
It also said that Israel, as the occupying power, had an obligation to ensure their basic needs were met, including by protecting medical personnel and allowing the rapid and unimpeded passage of humanitarian assistance throughout the Strip.
The ICRC said the intensification of military operations had forced it to suspend operations at its office in Gaza City as tens of thousands faced what it described as harrowing conditions.
The ICRC will continue to strive to provide support to civilians in Gaza City, whenever circumstances allow, from our offices in Deir al-Balah and Rafah [in central and southern Gaza], which remain fully operational, it added.