The first session of indirect Hamas-Israel ceasefire talks in Qatar ended inconclusively, two Palestinian sources familiar with the matter said early on Monday, adding that the Israeli delegation didn't have a sufficient mandate to reach an agreement with Hamas.

The deal comes more than 20 months into the conflict -- and more than three months after a previous deal ended.

As Israeli and Hamas negotiators meet in Qatar over a US-backed ceasefire agreement, some experts say there is reason for cautious optimism for a deal.