Indirect talks continue between Hamas, Israel in Cairo
Four weeks of fierce fighting have claimed more than 1,900 lives.
Egyptian officials, who brokered the 72-hour ceasefire that began on Tuesday, were working to persuade both sides to agree a long-term deal.
Israeli officials say they are willing to extend the ceasefire before it expires on Friday morning.
But Hamas, which controls Gaza, says there is no agreement and there is a big gap between the sides' positions.
The armed wing of Hamas has warned of renewed fighting if Israel does not end its blockade of Gaza's port.
Four weeks of fierce fighting between Israeli forces and Hamas have claimed more than 1,900 lives.