Talks in Cairo aimed at securing a fresh ceasefire in Gaza are under renewed strain, with both sides in the conflict issuing warnings.
Palestinian negotiators said they would leave on Sunday if Israel did not attend without preconditions.
Israel says it will not negotiate “under fire”, warning its military campaign “will take time”.
The UK, France and Germany have called for a new truce, after a 72-hour ceasefire ended on Friday morning.
Israeli Prime Minister Benjamin Netanyahu said in broadcast remarks at the weekly meeting of his cabinet in Tel Aviv: “The operation will continue until its objective – the restoration of quiet over a protracted period – is achieved.
“I said at the beginning and throughout the operation – it will take time, and stamina is required.”
More than 1,900 Palestinians – mostly civilians – been killed since violence erupted in Gaza in early July, according to the UN. Sixty-seven people have died on the Israeli side, including three civilians.
Israeli negotiators have already left Egypt and said they would not return to the indirect negotiations until rocket fire from Gaza stopped.
The Jerusalem Post quoted senior Israeli officials as saying that if rocket fire continued, “all options” were on the table, not just air strikes.
Communications Minister Gilad Erdan told Israel’s Channel 2 that “a wide ground incursion and the toppling of Hamas is being discussed”.
Hamas deputy chief Mussa Abu Marzuq accused Israel of stalling and said the next 24 hours would decide the fate of the Cairo talks.
Earlier, the foreign ministers of France (Laurent Fabius), of the UK (Philip Hammond) and of Germany (Frank-Walter Steinmeier) said that the only way to resolve the conflict was through talks.
“We call upon all parties immediately to return to a ceasefire. We fully support the ongoing efforts by Egypt to this end,” they said in a joint statement.
Earlier, the US and the United Nations issued a similar call for a ceasefire.
Hamas said Israel had failed to meet its key demands, including the lifting of the Gaza blockade and the release of prisoners. It also rejected Israel’s call for the demilitarisation of Gaza.
On Saturday, tens of thousands of protesters marched through London, Paris and Cape Town in what organisers called a “Day of Rage” against Israeli military action in Gaza.
About 150 protesters also held a demonstration in Tel Aviv, Israel, despite Israeli authorities banning the gathering.