Israel has said a four-day Gaza truce and hostage release will not start until at least Friday, stalling a breakthrough deal to pause the brutal and bloody seven-week-old war, according to AFP.

Israeli national security adviser Tzachi Hanegbi indicated the release of at least 50 Israeli and foreign hostages held by Hamas was on track, but would not happen until Friday at the earliest.

“The contacts on the release of our hostages are advancing and continuing constantly,” he said in a statement.

“The start of the release will take place according to the original agreement between the sides, and not before Friday.” A second Israeli official said that a halt in fighting would also not take place on Thursday, as had been expected.

Israel’s public broadcaster Kan, citing an unidentified Israeli official, reported there was a 24-hour delay because the agreement was not signed by Hamas and mediator Qatar. The official said they were optimistic the agreement would be carried out when it was signed, according to Reuters.