Gaza conflict: Israel and Hamas agree 12-hour window
The truce is due to begin at 0800 local time (0500 GMT). Efforts to negotiate a seven-day ceasefire are still ongoing.
Earlier US Secretary of State John Kerry said he was still confident of a longer ceasefire, despite media reports that Israel had rejected one proposal, BBC News reports.
More than 800 Palestinians, mostly civilians, and 36 Israelis have died since the conflict started on 8 July.
A spokesman for Hamas, the Islamist group that controls Gaza, Sami Abu Zuhri said there was "national consensus on a humanitarian truce... for 12 hours on Saturday".
The Israel Defense Forces (IDF) later confirmed the truce on Twitter , but said it would "continue to locate and neutralise terror tunnels".
"We will respond if terrorists choose to exploit this time to attack IDF personnel or fire at Israeli civilians," it said in a statement.
The news came shortly after Israeli Defence Minister Moshe Yaalon warned that ground operations in Gaza could soon be broadened "significantly".
