Yahya Sinwar, the Hamas leader, is blocking a deal to release Israeli hostages, the Biden administration has said.

An agreement to release the 133 hostages depends on “one guy”, an unnamed official said, in a change of tone from previous White House statements that have suggested that Benjamin Netanyahu, the Israeli prime minister, is delaying the process.

It came as 18 world leaders, including Rishi Sunak and Joe Biden, signed a joint letter urging Hamas to release the captives it has held for more than 200 days.

The official, who was not authorised to discuss the matter publicly, criticised Hamas officials for taking part in negotiations when only Sinwar, the leader of the terrorist group’s military wing, dictates policy.

“Ultimately Sinwar is the guy who says ‘yes’ or ‘no’,” they said.

Israeli media on Thursday evening reported that Egypt, a key mediator between Israel and Hamas, has offered a new ceasefire proposal to a visiting Israeli delegation.

Egyptian officials have suggested Israel agree to cancel the Rafah offensive and pledge a one-year ceasefire in exchange for the release of hostages, according to Yedioth Ahronoth newspaper.

An Egyptian delegation is expected in Israel on Friday to push the deal further.

Late on Wednesday, Hamas released the first proof-of-life videos for 24-year-old Hersh Goldberg-Polin who was captured in southern Israel on Oct 7. The dual Israeli-US national appeared pale and distressed.

“Sinwar made the decision he’d rather hold him and others rather than secure the ceasefire in Gaza – that’s the truth of the situation,” the US official said, adding that it appears that Mr Sinwar, one of the masterminds of the Oct 7 massacre, “seems determined to simply sit underground holding hostages, totally impervious to the conditions above ground for the people of Gaza”.

When asked about Israel’s stance, the US official indicated that Israel was being difficult early on in the talks but has now “fully agreed” to the US proposal on the table.

The joint call from the countries whose citizens either went missing or were kidnapped by Hamas in southern Israel on Oct 7 pressed Hamas to take the terms floated at the talks in Cairo.

The deal that Hamas recently rejected “meets nearly all [its] demands ”including the return of the displaced Palestinians – a previously contentious issue for Israel – according to the US official. But Hamas would first need to release female and child hostages as well as the elderly and wounded in captivity.

“Hamas is refusing to let hostages go back to their families – if they do that, this crisis will wind down – it’s a very clear path,” the official said.

Israel’s war cabinet was meeting on Thursday in a bid to begin the negotiations for the release of hostages, and two senior Israeli officials had left for Cairo to talk about resuming the talks.

A Hamas official indicated that the terrorist group is not going to give in to international pressure.

Sami Abu Zuhri told Reuters the US pressure on Hamas “has no value” and added that the group would keep on insisting that Israel end the war before it releases any hostages.

Also on Thursday, Mr Biden hosted Abigail Mor Edan, a four-year-old girl who survived Hamas captivity after she was abducted and both of her parents were killed.

Mr Biden was pictured standing in the Oval Office and holding the girl in his arms.

“She’s remarkable and recovering from unspeakable trauma,” the US president was quoted as saying.

Earlier, a senior Hamas official indicated that the terrorist group may be willing to lay down arms in exchange for the creation of a sovereign Palestinian state.

Khalil al Hayya, a Qatar-based member of the Hamas politburo, told AP that the group would disband its military wing if Israel were to agree to recognise the Palestinian state.

The moderate comments stand in contrast to the recent rhetoric of Hamas leaders inside Gaza and the group’s own charter that demands the liberation of Palestine “from the river to the sea”.