Israeli security and policy chiefs were expected to arrive in Qatar on Sunday for high-level talks about a proposed cease-fire deal in Gaza that would see hostages released in the final days of President Biden’s term and before Donald J. Trump takes office.

Biden administration officials have been pressing for a deal that would become part of the departing president’s legacy, and Mr. Trump has warned that “all hell will break out in the Middle East” if Hamas does not release the hostages before he is inaugurated on Jan. 20.

Lower-level negotiations have been underway in recent weeks after months of deadlock.

While some progress has been made, disagreements remain on several key points, including the timing and extent of Israel’s redeployments and withdrawal from Gaza and its willingness to ultimately end the war, according to several officials and a Palestinian familiar with the matter. They were speaking on the condition of anonymity because the talks are being held in secrecy and they were not authorized to discuss details publicly.

Representatives of the departing and incoming U.S. presidents have been cooperating on the issue, the Biden administration has said, while Qatar and Egypt are mediating between Israel and Hamas.

Steve Witkoff, Mr. Trump’s intended Middle East envoy, met Prime Minister Benjamin Netanyahu in Israel on Saturday. On Friday, Mr. Witkoff was in Doha, the capital of Qatar, and met the Qatari prime minister, Sheikh Mohammed bin Abdulrahman bin Jassim Al-Thani, for talks that focused on efforts to reach a cease-fire in Gaza, according to Qatar’s Foreign Ministry.