US officials now believe that a ceasefire deal between Israel and Palestinian Islamist group Hamas in Gaza is unlikely before President Joe Biden leaves office in January, the Wall Street Journal reported on Thursday.

The newspaper cited top-level officials in the White House, State Department and Pentagon without naming them. Those bodies did not immediately respond to requests for comment.

"I can tell you that we do not believe that deal is falling apart," Pentagon spokesperson Sabrina Singh told reporters on Thursday before the report was published.

US Secretary of State Antony Blinken said two weeks ago that 90% of a ceasefire deal had been agreed upon.

The United States and mediators Qatar and Egypt have for months attempted to secure a ceasefire but have failed to bring Israel and Hamas to a final agreement.

Two obstacles have been especially difficult: Israel's demand to keep forces in the Philadelphi corridor between Gaza and Egypt and the specifics of an exchange of Israeli hostages for Palestinian prisoners held by Israel.

The United States has said a Gaza ceasefire deal could lower tensions across the Middle East amid fears the conflict could widen.

Biden laid out a three-phase ceasefire proposal on May 31 that he said at the time Israel agreed to. As the talks hit obstacles, officials have for weeks said a new proposal would soon be presented.

The latest bloodshed in the decades-old Israeli-Palestinian conflict was triggered on Oct 7 when Hamas attacked Israel, killing 1,200 and taking about 250 hostages, according to Israeli tallies.

Israel's subsequent assault on the Hamas-governed enclave has killed over 41,000 Palestinians, according to the local health ministry, while displacing nearly the entire population of 2.3 million, causing a hunger crisis and leading to genocide allegations at the World Court that Israel denies.