Hamas submitted a new set of demands on Thursday, including calls for a large number of Palestinian prisoners to be released and an eventual agreement on a permanent ceasefire.

The response from Hamas was long-awaited after discussions over a proposed six-week pause in the fighting appeared to stall. The Biden administration has repeatedly said in recent weeks that the onus was on Hamas to respond and that Israel had generally agreed to a framework deal.

Hamas communicated their latest proposal via mediators Qatar and Egypt on Thursday, two sources familiar with the negotiations told CNN. On Friday, the office of Prime Minister Benjamin Netanyahu said that “Hamas is continuing to hold to unrealistic demands” but announced that an Israeli team would soon be traveling to Doha to further talks.

An agreement, if it happens, is expected to have multiple phases, and in the first stage, Hamas has proposed releasing the Israeli hostages who are women – including IDF soldiers – the elderly, sick and wounded. That number is believed to be around 40 out of the around 100 hostages who remain alive.

The latest proposal by Hamas demands that some 700 to 1,000 Palestinians prisoners be released, a diplomat familiar with the discussions told CNN, confirming earlier reporting by Reuters.

In a second phase, Hamas said that each side should release all remaining hostages and prisoners, which would include male IDF soldiers and more Palestinian prisoners. The Hamas proposal included 100 prisoners serving life sentences in Israeli prisons, the diplomat said.

But the toughest sticking points may be the Hamas demands that after the initial exchange of hostages and prisoners, Israel agree to a permanent ceasefire and a withdrawal of the Israeli military from Gaza. Israel’s government has repeatedly said those terms are unacceptable and that they still intend to continue the fight against Hamas until “complete victory.”

Israel’s leaders have also vowed to carry out a ground offensive in the southern Gaza city of Rafah, where almost 1.5 million Palestinians have sought refuge.

The diplomat familiar with the discussions said: “It is not going to be easy to convince Israelis of this [Hamas proposal].”

‘Tough negotiations are expected’

An Israeli official echoed the sentiment to CNN, predicting that “very tough negotiations are expected,” but said negotiators are going to Doha because Hamas finally delivered a response.

The team is expected to leave Israel at the beginning of next week, a second Israeli official said, and a decision will be made by the end of Saturday on the scope of what the Israeli negotiating team is allowed to agree to. Even if both Hamas and Israel are participating in the talks, the two sides would not be in the same room.

US Secretary of State Antony Blinken said Friday that the fact that Israel has sent a team to pursue the negotiations “reflects the sense both of possibility and of urgency to get an agreement, to get a ceasefire, to get the hostages back, to get even more humanitarian assistance in.”

“What I can tell you is we’re working intensively with Israel, with Qatar, with Egypt, to bridge the remaining gaps and to try to reach an agreement,” Blinken said.

CIA Director Bill Burns has been the Biden administration’s point person on ceasefire discussions and recently returned from a trip to Egypt, Qatar and Jordan, where he also met with Israeli Mossad director David Barnea.

The Biden administration is not planning on sending a team to Qatar for the next round of discussions, but on Friday, National Security Council spokesperson John Kirby said that Hamas’ response is “within the bounds of the deal that we’ve been working on now for several months. I don’t want to go into more detail than that,” he said, suggesting that the delegation heading to Doha for talks is a positive sign but that any ultimate agreement could change following negotiations.

“The fact that we’re physically not going to have a delegation there should not be taken as any kind of signal that this isn’t a serious, positive move forward. We think it could be,” Kirby told CNN’s MJ Lee at a White House press briefing.

The Biden administration has increasingly called for an “immediate ceasefire” of at least six weeks. They had set the beginning of Ramadan, earlier this week, as a goal for it to begin and expressed optimism that was possible. But the start of the Muslim holy month came and went without an agreement.

In an Oval Office meeting on Friday, Ireland’s prime minister called for a ceasefire “as soon as possible,” which Biden nodded to and said he agreed.

A senior Hamas official noted the White House’s characterization of their response, saying it “confirm[s] the seriousness of the [Hamas] movement in reaching an agreement for a ceasefire.”

“We will not accept anything less than an end to the aggression on Gaza, the return of the displaced, the withdrawal of the occupation, and the entry of humanitarian aid,” Basem Naim, a senior member of the group’s political bureau, told CNN.