The start of a short-term cease-fire between Israel and Hamas that will allow for the release of some hostages held in Gaza, the release of Palestinians being held by Israel and for more humanitarian aid to enter the Gaza Strip has been delayed until Friday, an Israeli official said.

"The contacts on the release of our hostages are advancing and continuing constantly. The start of the release will take place according to the original agreement between the sides, and not before Friday," an Israeli official said Wednesday in a statement.

The release of hostages, along with a four-day cease-fire, was originally set to begin Thursday morning.

According to the terms of the deal, Hamas will release 50 hostages, all women and children, over the course of the four days. Three Palestinian prisoners held by Israel will be released for every Israeli hostage released by Hamas. President Biden said three Americans are among those expected to be released by Hamas.

There is a possibility more could be released by both sides.

Israeli Prime Minister Benjamin Netanyahu said Tuesday that "the release of every additional ten hostages will result in one additional day in the pause."