The Israeli military says it has begun the "preliminary actions" of a planned ground offensive to capture and occupy all of Gaza City and already has a hold on its outskirts.
A military spokesman said troops were already operating in the Zeitoun and Jabalia areas to lay the groundwork for the offensive, which Defence Minister Israel Katz approved on Tuesday and which will be put to the security cabinet later this week.
About 60,000 reservists are being called up for the beginning of September to free up active-duty personnel for the operation.
Hamas has accused Israel of obstructing a ceasefire deal in favour of continuing a "brutal war against innocent civilians", Reuters news agency reported.
Hundreds of thousands of Palestinians in Gaza City are expected to be ordered to evacuate and head to shelters in southern Gaza as preparations for Israel's takeover plan get under way.
Many of Israel's allies have condemned its plan, with French President Emmanuel Macron warning on Wednesday that it "can only lead to disaster for both peoples and risks plunging the entire region into a cycle of permanent war".
