Explained | What we know about the proposed Gaza ceasefire agreement

The optimism of a Gaza ceasefire agreement was tempered by the uncertainty of whether both sides would ultimately agree, by what details could still change and by the experience of months past in which ceasefire talks repeatedly collapsed.

After more than 15 months of nearly uninterrupted fighting in the Gaza Strip, diplomats trying to broker a ceasefire between Israel and Hamas expressed cautious hope on Tuesday that a deal could finally be within reach.

But that optimism was tempered -- by the uncertainty of whether both sides would ultimately agree, by what details could still change and by the experience of months past in which ceasefire talks repeatedly collapsed.

"We believe that we are at the final stages, but until we have an announcement -- there will be no announcement," Majed al-Ansari, the Foreign Ministry spokesperson for one of the mediating countries, Qatar, told reporters Tuesday.

Here's what we know about the potential ceasefire agreement.

What is the state of the talks?

US Secretary of State Antony Blinken said Tuesday that Israel and Hamas were "right on the brink" of agreeing to a deal to pause the fighting in Gaza and release hostages held there in exchange for Palestinians held in Israeli jails.

He and diplomats from other mediating countries, including Qatar and Egypt, have for months failed to reach a breakthrough in talks, but they have made progress quickly in recent weeks.

Mediators "managed to minimize a lot of the disagreements between both parties," al-Ansari said, adding that they were focused on "the final details of reaching an agreement."

"On Sunday, the United States, Qatar and Egypt put forward a final proposal," Blinken said. "The ball is now in Hamas' court."

Officials in the Israeli government and Hamas have suggested that they are ready to move forward if the other side signs off.

On Monday, a Hamas official said a deal was possible in the coming days as long as Israel did not suddenly change its positions. On Tuesday, an Israeli official said Israel was ready to close the deal and was waiting for Hamas to make a decision.

Hamas officials negotiating in Qatar must obtain the consent of the group's remaining military commanders in Gaza for the deal. Those commanders include Mohammad Sinwar, whose brother led the group before being killed by Israel in September. Because of their need to keep their locations secret, communicating with them can be difficult, causing delays.

It was still not clear whether Sinwar had conveyed his position toward the ceasefire proposal to Hamas leaders in Qatar.

What does the proposal say?

Given the sensitive, continuing negotiations, officials have been wary of describing the proposed agreement except in broad terms.

The framework of the deal was heavily inspired by previous proposals discussed in May and July, said one diplomat familiar with the talks, speaking on condition of anonymity to discuss the volatile negotiations. Those proposals detailed a three-stage ceasefire in which Israeli troops would gradually withdraw from Gaza as Hamas released hostages in exchange for Palestinians jailed by Israel.

Israeli officials hope to secure the release of at least some of the approximately 100 hostages who have been held in Gaza since the Hamas-led attack on southern Israel in October 2023 that started the war. About 35 of the remaining hostages are presumed dead by Israeli authorities.

Hamas leaders want to end Israel's military campaign, secure the entry of materials for reconstruction and gain the freedom of Palestinian prisoners held in Israel.

During the first phase of the proposed ceasefire -- which would last roughly six weeks -- Hamas would release 33 named hostages, most of whom Israel believes are alive, said an Israeli official, who requested anonymity to discuss the sensitive talks. Israel is willing to release hundreds of Palestinian prisoners in exchange, the official said, but the number depends on how many of the hostages are still alive.

Why have talks moved swiftly in recent weeks?

Some officials have suggested that the change in U.S. administrations, set to take place Jan. 20, put pressure on Israel and Hamas to accelerate their decision-making after months of delay.

The incoming US president, Donald Trump, has warned that there will be "all hell to pay" unless the hostages are freed by the time he becomes president. Steve Witkoff, his pick for Middle East envoy, has also made trips to Qatar and Israel.

The talks have also gained momentum since Israel reached a separate ceasefire agreement with the Lebanese militant group Hezbollah, which began firing rockets into Israel immediately after the Hamas-led attack of October 2023. Battered badly by its escalating conflict with Israel, Hezbollah agreed to a ceasefire with Israel in November, a deal that helped isolate Hamas.