The prime minister's office did not elaborate on the decision on Sunday, but warned of "additional consequences" if Hamas does not accept what Israel says is a US proposal for an extension of the ceasefire.
It was not immediately clear if the supply of aid had been completely halted.
The first phase of the Israel-Hamas ceasefire, which included a surge in humanitarian assistance, expired on Saturday.
The two sides have yet to negotiate the second phase, in which Hamas was to release dozens of remaining hostages in return for an Israeli pullout and a lasting ceasefire.
Earlier Israel said it would adopt a US proposal for a temporary ceasefire in Gaza for the Ramadan and Passover periods.
The proposal by US President Donald Trump's envoy, Steve Witkoff, was agreed to early on Sunday, hours after the first phase of the previously agreed ceasefire was set to expire.
Hamas said Israel's decision on Sunday affects the ceasefire negotiations, adding that the Palestinian Islamist group does not respond to pressure.
"This decision complicates matters and affects the negotiation process, and Hamas doesn't respond to pressures," senior Hamas official Sami Abu Zuhri told Reuters.
Netanyahu's office said Israel would immediately conduct negotiations on Witkoff's plan if Hamas agreed to it.
"According to the agreement, Israel can return to fighting after the 42nd day if it feels that the negotiations are ineffective," Netanyahu's office also said, accusing Hamas of violating the deal. Both sides have been trading accusations of violating the deal.
The ceasefire agreement reached in January halted 15 months of fighting, allowing the exchange of 33 Israeli hostages and five Thais for around 2000 Palestinian prisoners and detainees. It was meant to lead to subsequent talks to build on the ceasefire deal.
Talks about the ceasefire have been ongoing, most recently in Cairo, but have not led to an agreement.
Egyptian sources said on Friday the Israeli delegation sought to extend the first phase by 42 days, while Hamas wanted to move to the second phase of the ceasefire deal. Spokesman Hazem Qassem said on Saturday the group rejected Israel's "formulation" of extending the first phase.
with AP
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