Benjamin Netanyahu has claimed Hamas has backtracked on an earlier understanding of the ceasefire agreement, which is awaiting the approval of the Israeli government.
The Israeli prime minister said the group was objecting to part of the agreement which would give Israel the ability to veto the release of certain Palestinian prisoners.
Hamas was trying to dictate which Palestinian prisoners would be released, he said.
Follow live: Gaza ceasefire deal
“Among other things – contrary to a specific clause that grants Israel the veto power over the release of mass murderers who are symbols of terrorism, Hamas is demanding to dictate the identities of these terrorists,” the prime minister’s office said in a statement.
It said Mr Netanyahu has told Israeli negotiators to stand firm on the earlier agreement. Hamas is yet to respond.
Any deal will need to be approved by Mr Netanyahu’s security cabinet and then his government.
Since the agreement has been announced at least 32 people have been killed in heavy Israeli bombardment in Gaza, medics reported.
Strikes continued into Thursday morning, flattening houses in Rafah in southern Gaza, Nuseirat in central Gaza and in northern Gaza, local residents said.
The ceasefire deal does not come into force until Sunday.
The announcement comes after weeks of painstaking negotiations in Doha against the backdrop of a war in Gaza that has left tens of thousands of Palestinians dead and many more injured and displaced from their homes.
Much of the densely-populated territory has been razed to the ground as Israel launched a ground offensive following the Hamas attacks on 7 October 2023 which left 1,200 people dead and around 250 people taken hostage.
Read more:
A timeline of events in more than a year of war
Faces of 94 hostages who still haven’t returned home
What does the agreement say?
The war in numbers
What’s in the deal?
The deal outlines a six-week initial ceasefire phase that includes a gradual withdrawal of Israeli forces from central Gaza and the return of Palestinians to north Gaza, the Reuters news agency reported, citing an official briefed on the agreement.
Hamas will release 33 hostages, including all women, children and men over the age of 50, the agency said.
In return for the release of the hostages, Israel will free between 990 and 1,650 Palestinian prisoners and detainees.
Israel will release 30 Palestinian detainees for every civilian hostage and 50 Palestinian detainees for every female Israeli soldier that Hamas releases.
There will also be a surge of humanitarian aid allowed into Gaza as part of the agreement, which requires 600 aid trucks to be allowed into Gaza each day.
Negotiations over a second phase of the agreement are to begin on the 16th day of phase one and are expected to include the release of all remaining hostages, including male Israeli soldiers, a permanent ceasefire and the complete withdrawal of Israeli forces.
A third phase is expected to include the return of the bodies of the dead hostages and the beginning of Gaza’s reconstruction, supervised by Egypt, Qatar and the UN.
Analysis: This deal wouldn’t have happened without Trump
Shortly after the ceasefire deal was announced, Hamas’ acting Gaza chief Khalil al-Hayya said in a televised address that Israel failed to achieve its goals in the Palestinian territory.
He also vowed Hamas will neither forgive nor forget Israel’s actions in Gaza.