US President Joe Biden has said Israeli Prime Minister Benjamin Netanyahu is not doing enough to secure a hostage deal and ceasefire with Hamas, amid reports that a new “final” proposal would be sent to the Israeli leader.

Mr Biden and Kamala Harris, his vice-president, met US negotiators to hammer out a proposal, as protests engulfed Israel on Monday after the discovery of six more hostage bodies in Gaza.

Asked whether Mr Netanyahu was doing enough, Mr Biden replied “no”. He added that the US would not give up, and would “push as hard as we can” for a deal.

US officials have characterised this latest proposal as a “take it or leave it deal”, the Washington Post has reported.

Among the bodies recovered from Gaza on Saturday was that of 23-year-old Israeli-American Hersh Goldberg-Polin.

He became one of the most recognisable hostages in the crisis after being seized by Hamas gunmen at a music festival in southern Israel on 7 October last year.

The discovery of the bodies has caused widespread protests in Israel from those critical of Mr Netanyahu’s handling of the war and hostage crisis.

On Monday, thousands of people joined a strike called by the country’s biggest trade union, in an effort to put pressure on Mr Netanyahu to close out a deal.

Goldberg-Polin’s funeral was held in Jerusalem on the same day, attended by thousands.

His mother Rachel – who also spoke at last month’s Democratic convention in the US – described her torment. President Isaac Herzog offered an apology that his country had “failed” to protect Goldberg-Polin or bring him home.

In comments of his own on the same day, Mr Netanyahu appealed to Israelis for “forgiveness” over the group’s deaths.

Mr Biden said the US was “devastated and outraged” by the death of Mr Goldberg-Polin and the five others. “Make no mistake, Hamas leaders will pay for these crimes,” he said.

Mr Biden spoke after Monday’s meeting with negotiators in the White House Situation Room. US officials said he and Ms Harris discussed next steps in the effort to release of the hostages, including continuing talks with co-mediators Qatar and Egypt.

Mr Biden is expected to present a “final” hostage release and ceasefire proposal later this week, according to the Axios website, which cited US National Security Advisor Jake Sullivan in conversation with the US families of remaining hostages.

The US family of Edan Alexander, a member of the Israeli military who is still a hostage in Gaza, have pushed for Israel to accept the deal, saying it is “now or never”.

His father Adi Alexander praised the US for its “dedication and commitment” to secure a deal, saying that his meeting on Sunday was his 15th with Mr Sullivan since 7 October last year.

But in an interview with BBC’s US partner CBS News on Monday, Mr Alexander appealed to US officials to “do something different, because the outcome is the same after 11 months”.

Mr Alexander accused Mr Netanyahu of “prolonging the war for short-term political gain”. He added: “Time is passing by and we’re getting more bodies out of Gaza. This is unacceptable.”

In its report, the Washington Post reported that the killing of the six hostages had increased the urgency among Mr Biden’s aides to push for a deal.

“You can’t keep negotiating this. This process has to be called at some point,” one senior official told the newspaper.

“Does it derail the deal? No. If anything, it should add additional urgency in this closing phase, which we were already in,” they added.

The US, Qatar and Egypt have for months tried to secure a deal that includes a ceasefire in Gaza and the release of the remaining hostages held by Hamas.

The Biden administration has criticised Hamas for failing to agree to a deal, though US foreign officials have also accused Mr Netanyahu of making demands that have also derailed efforts.

The war in the Gaza Strip began after the Hamas breached the Gaza boundary, killed 1,200 Israelis and abducted 251 in their attack last year.

Israel has since killed over 40,000 Palestinians in retaliatory attacks, according to the Hamas-run Gaza health ministry.

The US response to the war has had implications for the Biden administration and Ms Harris, the Democratic nominee in November’s US presidential election. Pro-Palestinian factions in the party have urged for a ceasefire.

Ms Harris’s opponent, Republican nominee Donald Trump, has blamed Ms Harris and Mr Biden’s failure to secure a deal for the hostage deaths last weekend.