Efforts to get hostages out of Gaza complicated by Israel’s expanding ground operation

US officials are intently focused on trying to secure the release of hostages being held by Hamas in Gaza – among them American citizens – a task that sources said is now further complicated by Israel’s expansion of its ground operations into Gaza.

The US remains a part of the ongoing talks that include Israel, Qatar, Egypt and Hamas to get a large group of hostages out of Gaza, and officials are now contending with Israel pressing forward with ground operations into the strip. Biden administration officials have been calling on Israel to consider so-called humanitarian pauses that can allow for civilians in Gaza, including hostages, to exit, and for aid to get in.

Offering a glimpse into how unpredictable and fluid the situation remains, a senior US official told CNN on Monday that they believed the prospects of getting hostages out could be described as “50/50.”

“The parameters are all there,” this official said about a potential deal. But efforts to negotiate with Hamas – mediated significantly by the Qataris – has been slow-going, in no small part because it simply takes a long time for messages to be transmitted from Doha to Hamas.

Majed Al-Ansari, the spokesperson for Qatar’s Ministry of Foreign Affairs and adviser to the Qatari prime minister, told CNN on Saturday that Israel’s escalation on the ground is making the situation “considerably more difficult.”

Israel has said intensifying ground offensive puts additional pressure on Hamas, and therefore may ultimately be helpful in the ongoing efforts to free hostages. A US official said there could in fact be some benefit to this approach.

President Joe Biden’s national security adviser Jake Sullivan said on CNN’s “State of the Union” Sunday that Hamas has “not been forthcoming about allowing these hostages to go,” but that the administration believes there is still a “pathway” for securing their release.

“Even though we’ve started to see Israel moving on the ground, that has not changed our basic view that this has to remain a paramount priority that we have to keep working at,” Sullivan said.

One source familiar with the discussions said the talks have centered on freeing hostages in exchange for prisoners being held by Israel. Al-Ansari, the Qatari spokesperson, also said that there have been active discussions about a “prisoner exchange” for the hostages. The source added the negotiations also include getting Hamas to open the Rafah gates for dual nationals to get out of Gaza.

“We are optimistic that the talks are headed more towards all civilian hostages,” al-Ansari said. “But obviously, it is a fluid situation on the. And we still don’t know will happen.”

As the talks continue, there remains real skepticism about how serious Hamas is about the negotiations, the senior US official said. “It’s Hamas after all.”

CNN’s Alex Marquardt and Becky Anderson contributed to this report.

For more CNN news and newsletters create an account at CNN.com