Israel has said Hamas had yet to clarify whether 34 hostages it claimed it was ready to free were dead or alive, throwing doubt on the group's assertion that it needed time to ascertain their fate.
The offer from Hamas came as Israel continued to pound the Gaza Strip, where rescuers said 13 people were killed.
In the occupied West Bank, where violence has surged since the war in Gaza broke out, Israeli officials said three people were killed in an attack by gunmen.
Mediators from Qatar, Egypt and the United States have been working for months to strike a deal to end the fighting in Gaza, but both warring sides have accused the other of derailing the negotiations.
In recent days, mediators have resumed indirect talks, and a senior Hamas official said that the group was prepared to release an initial batch of captives but would need "a week of calm" to determine whether they were still alive.
Israeli government spokesman David Mencer, however, has rejected that claim.
"They know precisely who is alive and who is dead. They know precisely where the hostages are," Mr Mencer told journalists in an online briefing.
"Gaza is a very small place. Hamas know exactly where they are."
In an earlier statement, Prime Minister Benjamin Netanyahu's office said Israel had not received any confirmation or comment by Hamas regarding the status of the hostages, adding those slated for inclusion were part of a list "originally given by Israel to the mediators" last year.
The Hamas official, requesting anonymity to discuss the ongoing negotiations, had also said the group came from a list presented by Israel, and would include all the women, children, elderly and sick captives still held in Gaza.
"Hamas has agreed to release the 34 prisoners, whether alive or dead," the official told AFP, but the group needed time "to communicate with the captors and identify those who are alive and those who are dead".
'Ceasefire now'
During their 7 October 2023 attack on Israel, which sparked the war in Gaza, Palestinian militants seized 251 hostages, of whom 96 remain in Gaza. The Israeli military says 34 of those are dead.
Israeli campaign group the Hostages and Missing Families Forum has called for a "comprehensive agreement" to secure the release of hostages.
"We know more than half are still alive and need immediate rehabilitation, while those who were murdered must be returned for proper burial," it said in a statement.
Since the war broke out, there has been only one truce in November 2023 that saw 105 hostages freed, including scores of Israelis handed over in exchange for 240 Palestinians released from Israeli jails.
US Secretary of State Antony Blinken voiced confidence that a ceasefire deal would come together, but possibly after President Joe Biden leaves office on 20 January.
"If we don't get it across the finish line in the next two weeks, I'm confident that it will get its completion at some point, hopefully sooner rather than later," Mr Blinken said on a visit to Seoul.
President-elect Donald Trump, who takes over on 20 January, has vowed even stronger support for Israel and has warned Hamas of "hell to pay" if it does not free the hostages.
UN World Food Programme accuses Israel of firing on Gaza convoy
Meanwhile, the UN's World Food Programme (WFP) has accused Israel of firing on one of its aid convoys in Gaza, saying at least 16 bullets hit the clearly marked vehicles but no staff were injured.
Condemning the "horrifying" and "unacceptable" incident, the WFP called again for "all parties to respect international humanitarian law, protect civilian lives, and allow safe passage for humanitarian aid."
The "clearly marked WFP convoy was shot at by Israeli forces near the Wadi Gaza checkpoint, putting the lives of our staff at tremendous risk and leaving the vehicles immobilized," the agency said in a statement.
"The convoy, consisting of three vehicles carrying eight staff members, came under hostile fire despite having received all of the necessary clearances from Israeli authorities.
"At least 16 bullets struck the vehicles," it added.
"Thankfully, no staff members were injured in this terrifying encounter."
The incident came after the WFP said gunmen attacked one of its convoys in December, leaving two people dead in the looting.
Strikes in Gaza
Israeli forces kept up their bombardment of Gaza, with the territory's civil defence agency reporting 13 people killed in strikes in the territory.
In the West Bank, gunmen killed three people when they opened fire on a bus and other vehicles near the village of Al-Funduq, Israeli emergency service providers said.
"We will reach the despicable murderers and hold them, as well as anyone who assisted them, accountable," Netanyahu said in a statement from his office.
Hamas's October 2023 attack on Israel resulted in the deaths of 1,208 people, mostly civilians, according to official Israeli data.
Since then, Israel's military offensive has killed 45,854 people in Gaza, a majority of them civilians, according to figures from the territory's health ministry that the United Nations considers reliable.
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