Israel's Cabinet has decided to extend a humanitarian ceasefire for 24 hours, but troops will respond to any fire from Gaza, a government official said.
He wrote in a text message that the truce would be extended until midnight local time tomorrow (9pm GMT).
He says Israel will continue to demolish Hamas military tunnels during the period of lull.
Earlier, Hamas had rejected a four-hour extension of today's initial 12-hour truce, and Gaza militants said they fired several dozen rockets at Israel.
There was no immediate Israeli retaliation for the rocket fire.
In Paris, US secretary of state John Kerry and European foreign ministers met earlier to find ways to transform the initial 12-hour lull into a sustainable truce.
In Gaza, thousands of residents who fled the violence streamed back to devastated border areas during the ceasefire to find large-scale destruction.
Fighting had pulverised scores of homes, wreckage blocked roads and power cables dangled in the streets.
In the northern town of Beit Hanoun, Siham Kafarneh, 37, sat on the steps of a small grocery, weeping. The mother of eight said the home she had spent 10 years saving up for and moved into two months earlier had been destroyed.
"Nothing is left. Everything I have is gone," she said.
More than 1,000 people, mainly civilians, have been killed and more than 6,000 have been wounded over the past 19 days, Palestinian health official Ashraf al-Kidra said.
Israeli strikes have destroyed hundreds of homes, including close to 500 in targeted hits, and forced tens of thousands of people to flee, according to Palestinian rights groups.
Across Gaza, more than 130 bodies were pulled from the rubble today, officials said. In southern Gaza, 20 members of an extended family were killed before the start of the lull when a tank shell hit a building where they had sought refuge, Mr al-Kidra said.
Israel says it is doing its utmost to prevent civilian casualties, including sending evacuation warnings to residents in targeted areas, and blames Hamas for putting civilians in harm's way.
Israel has lost 40 soldiers and two civilians, and a Thai worker also has been killed.
"There is no proof that any kind of gratuitous damage is being inflicted," said Israeli politician Ofer Shelah of the centrist Yesh Atid party.
I srael launched a major air campaign in Gaza on July 8 and later sent ground troops into the Hamas-ruled territory in an operation it said was aimed at halting Palestinian rocket fire and destroying cross-border tunnels used for attacks.
In Paris, Mr Kerry met European foreign ministers and later met foreign ministers from Qatar and Turkey to try to salvage truce efforts.
Yesterday, Israel rejected a proposal by Mr Kerry and UN chief Ban Ki-moon to halt fire for a week and to begin talks during this period on easing the border blockade of Hamas-ruled Gaza.
Hamas has said it would not halt fire until it won guarantees that the border blockade, enforced by Israel and Egypt, would be lifted.