Israel says goods border crossings with the Gaza Strip will remain closed, but its defence minister will hold talks to decide whether to allow fuel shipments.
Some areas of Gaza have seen blackouts in the past 24 hours because of fuel shortages at the local power plant.
The Gaza electricity company has warned that it may be forced to cut off power supplies completely unless it receives more fuel.
Shipments were halted last week after fierce border clashes and rocket fire.
The Israeli military staged an incursion into Gaza and sent air strikes, killing at least seven Palestinian militants, while militants fired a barrage of rockets into southern Israel.
Israel ordered the latest closure after Palestinian militants fired a rocket on Sunday, that landed without causing casualties.
“Defence Minister Ehud Barak’s directive to shut the crossings between Israel and the Gaza Strip will remain in place on Monday,” a senior official said.
Mr Barak was scheduled to hold meetings to decide whether to allow the opening of the Nahal Oz fuel terminal, the official added.
The United Nations told the BBC that one turbine at the Gaza plant was shut down on Sunday taking the output down from a possible 65 megawatts to 45 megawatts.
A second turbine is scheduled to be shut down on Monday evening, taking the output down to 25 megawatts.
If there are no fuel deliveries then the final turbine will be shut down on Tuesday, the UN said.
The Gaza City plant provides about a quarter of Gaza’s electricity, and more than half the electricity used by the city itself.
Most of the rest of the supply to the territory of 1.5m people comes directly via power lines from Israel.
Palestinian engineers have been implementing a system of rolling blackouts to different areas of Gaza City to prevent the lines from Israel becoming overloaded and cutting out.
Without a grid system, they have no way to divert power to essential utilities such as hospitals or sewage treatment works, and aid agencies warn of a serious threat to public health if the plant goes offline.
Oxfam says Gaza’s seven largest hospitals have got stocks of diesel to supply generators for about a week, although one of the smaller ones – al-Quds hospital – had only 36 hours’ supply.
It says the water utility has no stocks of fuel for generators which means the sewage disposal system will break down as soon as mains electricity is cut.