A Hamas official has said that the group could not agree to a deal that does not secure a clear Israeli position on a permanent ceasefire and complete withdrawal from Gaza.
"We asked the mediators to get a clear Israeli position to commit to a permanent ceasefire and a complete withdrawal from Gaza," Osama Hamdan told a press conference in Beirut.
It comes as Israeli Prime Minister Benjamin Netanyahu's biggest coalition partner earlier said it would support the prospective deal - which would involve freeing hostages from Hamas captivity - even if it entails an overhaul of Israel's Gaza war strategy.
The statement by Shas, an ultra-Orthodox Jewish party that holds 11 of the parliament's 120 seats, followed similar remarks yesterday by Yitzhak Goldknopf, leader of the second such party in the coalition, United Torah Judaism, which has seven seats.
"Our position is that there is nothing greater than the value of life and the commandment to redeem captives, because their lives face a real and present danger," Mr Goldknopf, Israel's housing minister, said in a statement.
Similarly citing a religious obligation, Shas pledged "full support" to the proposal.
It encouraged Mr Netanyahu and his war cabinet to "withstand all pressures for the end of returning the hostages".
The combined support of the two parties - which hold 18 of the 72 seats controlled by Mr Netanyahu's expanded emergency government - could help offset opposition by far-right partners to a US-backed proposal for winding down the Gaza war.
The deal's opponents - the Jewish Power party of National Security Minister Itamar Ben-Gvir and the Religious Zionism party of Finance Minister Bezalel Smotrich - control 13 seats and have threatened to quit the government over the deal.
They worry that the proposal would halt efforts to defeat the Palestinian Islamist group Hamas.
Mr Netanyahu has said Israel would not stop the war without toppling and disarming Hamas - while Hamas insists that any deal must end the Israeli offensive against it in Gaza.
Though the Israeli public has rallied around the war triggered by the 7 October Hamas attack, support has eroded amid worry for the 120 remaining hostages, more than a third of whom are believed to have died.
According to a poll aired by public broadcaster Kan on Sunday, 40% of Israelis support the ceasefire proposal, which was unveiled by US President Joe Biden last week, while 27% are opposed and 33% undecided.
40% of respondents said they believe that if Israel enters the deal that would spell an end to the war, while 34% predicted a resumption of fighting and 26% were undecided.
Asked if Israel would succeed in toppling Hamas, 32% said yes, 42% said no and 26% were undecided, Kan found.
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Israel mourns hostages
Meanwhile, Israel has mourned four hostages reported dead in Gaza amid growing doubts and international pressure over a plan for a ceasefire and hostage release deal outlined by US President Joe Biden.
Yesterday, Israel's military announced the deaths in Gaza of four hostages seized during the 7 October Hamas attack on Israel, naming them as Chaim Perry, Yoram Metzger, Amiram Cooper and Nadav Popplewell.
Their bodies were still in the hands of Hamas, it added.
Mr Cooper, 84, Mr Metzger, 80, and Mr Perry, 80, were abducted from the Nir Oz kibbutz while Israeli-British citizen Mr Popplewell, 51, was kidnapped from the Nirim kibbutz.
British Foreign Secretary David Cameron said he was "greatly saddened to hear about the death" of Mr Popplewell, adding: "we reiterate our demand for Hamas to send all hostages home".
"They should have returned alive to their country and their families," the Hostages Families Forum said.
The US has said that it wants the United Nations Security Council to adopt a resolution backing the proposal outlined by Mr Biden to end fighting between Israel and Palestinian militants Hamas in Gaza.
It circulated a one-page draft text, seen by Reuters, to the 15-member council.
A resolution needs at least nine votes in favour and no vetoes by the US, France, Britain, China or Russia to pass.
The draft calls on Hamas to accept the deal and "fully implement its terms without delay and without condition".
It also "stresses the importance of the parties adhering to the terms of the deal once agreed, with the aim of bringing about a permanent cessation of hostilities".
The US proposal comes a week after Algeria proposed a draft Security Council resolution demanding a Gaza ceasefire, release of all hostages held by Hamas and essentially ordering Israel to "immediately halt its military offensive" in Rafah.
Mr Biden on Friday laid out what he described as a three-phase Israeli proposal for a ceasefire in Gaza in return for the release of Israeli hostages, saying "it's time for this war to end" and winning a positive initial reaction from Hamas.
Leaders of the G7 major democracies said in a statement that they "fully endorse and will stand behind the comprehensive" ceasefire and hostage release deal.
The foreign ministers of Saudi Arabia, Jordan, the United Arab Emirates, Qatar and Egypt said it was important to "deal seriously and positively".
Rockets from Lebanon strike Israel causing forest fires
Israeli authorities are battling intense forest fires in the north of the country that broke out shortly after rocket and drone strikes from neighbouring Lebanon struck the area, forcing the partial evacuation of one town.
Israeli police said that several homes in Kiryat Shmona had been evacuated.
An AFP photographer in the northeastern town saw intense blazes engulfing parts of the area bordering Lebanon, the scene of near-daily exchanges of fire between the Israeli military and the Iran-backed Hezbollah militant group on the sidelines of the war in Gaza.
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The Israeli military said it had deployed reinforcements to support firefighters overwhelmed by the scale of the fires.
"Six IDF reservist soldiers were lightly injured as a result of smoke inhalation and transferred to a hospital to receive medical treatment," the military said.
"The forces gained control over the locations of fire, and at this stage, no human life is at risk," it added.
Leaders of the army's Northern Command had arrived in Kiryat Shmona during the night and the army was "conducting a situational assessment" in the sector.
The office of Mr Netanyahu said it was closely monitoring, together with the army, the development of the fires, which broke out yesterday after rocket fire and the fall of drones launched from Lebanon.
In retaliation, the Israeli military announced it had carried out air strikes against what it said were Hezbollah targets in southern Lebanon.
