Efforts to secure the release of hostages held in Gaza and broker a prolonged pause in fighting are at an important juncture as President Joe Biden deploys his point person on hostage talks to Europe for multiparty talks on the contours of a possible agreement.

CIA Director Bill Burns’ meetings over the coming days with the Israeli and Egyptian intelligence chiefs and the Qatari prime minister are a sign of ongoing progress as the White House presses for a deal.

Whether they prove decisive in striking an agreement remains to be seen, and officials voiced caution that discussions so far have been volatile, and that hurdles remain in coming to a deal that all sides can agree on.

Among the central sticking points: Israel has been adamant that it cannot agree to a permanent ceasefire in Gaza, which has been a key demand of Hamas. It’s unclear how that major difference would be resolved.

Still, progress has been made on the parameters of a hostage deal that would occur in three stages, and include the release of civilians, soldiers and the bodies of those hostages who have died while being held in captivity.

Burns’s meetings with Mossad director David Barnea, Egyptian intelligence director Abbas Kamel and Qatari Prime Minister Mohammed bin Abdulrahman Al Thani are expected to take place in France over the weekend, according to two sources familiar. The CIA declined to comment on his travel.

Burns and Barnea were central to a November agreement that resulted in a week-long pause in fighting in exchange for the release of more than 100 hostages.

The talks are the latest in a spate of recent diplomatic efforts to free the more than 100 remaining hostages while moving toward a more prolonged cessation of hostilities. The flurry of activity amounts to the most intensive effort in months to strike an agreement that could significantly alter the trajectory of the war in Gaza.

Speaking from the White House on Friday afternoon, National Security Council spokesman John Kirby described the ongoing talks as productive but not yet reaching the point of success.

“We’re hopeful about the progress, but I do not expect – we should not expect – any imminent developments,” Kirby said.

He said on Friday, Biden had spoken to Egypt’s President Abdel Fatah al-Sisi as well as Qatar’s Emir Sheikh Tamim bin Hamad Al Thani to discuss ongoing hostage talks.

“We continue to do everything we can to facilitate another hostage deal just like we did back in November,” Kirby said.

A readout from the White House Friday said that Biden and Al Thani “affirmed that a hostage deal is central to establishing a prolonged humanitarian pause in the fighting and ensure additional life-saving humanitarian assistance reaches civilians in need throughout Gaza.”

Both leaders “underscored the urgency of the situation” in their conversation, the readout noted.

Kirby also said Brett McGurk, the White House coordinator for the Middle East, was returning to Washington on Friday from meetings in the region.

He described those talks as a “good set of discussions.”

“At every level, from the president right on down, we’re doing everything we can to bring these moms and dads, sons and daughters, brothers and sisters back home to their families,” Kirby said. “Our thoughts remain with them, of course their loved ones, as well as all of the innocent Palestinians that continue to be caught up in this war.”

Qatar’s prime minister is expected to travel to Washington next week, a diplomatic source told CNN. Qatar has acted as a key broker in talks with Hamas.

US officials are now hopeful for a much longer cessation in the fighting, believing it could provide space for more humanitarian aid to flow into Gaza as well as continued discussions about the future of Israel’s campaign against Hamas and the future of Gaza.

Qatar, Egypt and the US have been working toward trying to find common ground in proposals that were put forward several weeks ago by both Hamas and Israel, according to an official familiar with the ongoing discussions. In the past week, Qatar sent back ideas to each of them, including a time frame of a two-month ceasefire that would see hostages released in phases.

First to be released would be the remaining women, children and the elderly, followed by another phase that would include Israeli soldiers and the bodies of dead hostages.

In exchange, Palestinians held in Israeli jails would be released in around a three-for-one exchange, akin to the deal struck last year, a second source familiar with the matter said, who said the process would take around a month.

Each stage would come with a pause in fighting and the delivery of aid to the North and South of Gaza.

Obstacles remain

The major sticking point for Hamas has been Israel’s refusal to discuss an end to the war past a temporary ceasefire. Israel’s focus, the official said, has been to try to discuss one phase at a time – with accompanying pauses and prisoner releases - while Hamas has pushed for a comprehensive plan that would include Israel agreeing to end the war against Hamas.

As part of proposals currently being discussed, the end of the hostage release process would come with a permanent ceasefire, a step Israel has been unwilling to agree to.

Israeli Prime Minister Benjamin Netanyahu and his defense minister, Yoav Gallant, have said the war may continue for the rest of the year, if not into 2025. And Netanyahu has been increasingly public in his rejections of a Palestinian state, a priority item for Biden and the US.

The Biden administration has been openly pressuring Israel to transition to a lower-intensity phase of operations, including in telephone calls between Biden and Netanyahu.

Aside from the Biden administration’s own interest in seeing a half dozen Israeli-American hostages released, US officials see a ceasefire deal and hostage release as the key to getting to a significant pause in the fighting that will help the flow of humanitarian aid and allow Palestinians to return to their homes, many of which have been destroyed.

But with two key parties who have their own priorities, in addition to at least three main mediators, there is a complex array of ideas, proposals and initiatives being put forward.

“These things are very fluid, they change every single minute,” the official said.

Whether all parties can reach an agreement remains to be seen, and the talks will occur against the backdrop of renewed tensions between Israel and Qatar, sparked by leaked recording purported to be Netanyahu criticizing the Gulf state.

Burns and McGurk’s discussions with regional players come amid tensions between Israel and Qatar over a leaked recording said to be of Israeli Prime Minister Benjamin Netanyahu criticizing Qatar.

On the recording, which aired on Israeli television, a voice purportedly Netanyahu’s describes Qatar as “problematic.” The speaker also says he is “very mad at the Americans” for renewing a lease on their military base in Qatar without extracting a concession on hostages from the country. CNN cannot verify that the voice on the leaked recording belongs to Benjamin Netanyahu.

Responding to the tape, Qatar said Netanyahu was undermining mediation efforts in the Israel-Hamas war.

The White House on Thursday reiterated its gratitude for Qatar — which has acted as a key mediator in hostage talks — in response to the leaked recording.

“Qatar is a key partner in the region. We’re grateful for their support of our continued efforts to try to get hostages out of Gaza and reunited with their families,” Kirby said in a statement Thursday evening.