Israel has said it is stopping the entry of all goods and supplies into the Gaza Strip.
Prime Minister Benjamin Netanyahu’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 is expected to release dozens of remaining hostages in return for an Israeli pullout and a lasting ceasefire.
Israel said earlier on Sunday that it supports a proposal to extend the first phase of the ceasefire through Ramadan and Passover, or April 20. It said the proposal came from the Trump administration’s Middle East envoy, Steve Witkoff.
Under that proposal, Hamas would release half the hostages on the first day and the rest when an agreement is reached on a permanent ceasefire, according to Mr Netanyahu’s office.
Hamas has not yet responded to the proposal.