Fresh Israeli air strikes on Gaza pushed the Palestinian death toll to more than 300 on Friday.
One Israeli soldier has been killed by accidental Israeli fire.
40,000 Palestinians have now taken refuge in UN shelters within Gaza.
At an emergency session of the UN, both the Palestinian and Israeli representatives made their pleas to the world.
Israeli UN ambassador, Ron Prosor, said: “Each and every missile constitutes a crime against humanity, whether it hits or misses, because it is directed at civilian targets”.
Meanwhile the Palestinian UN ambassador, Riyad Mansour, said: “This savage Israeli aggression cannot be justified by any means. It is not self-defence – it is a vengeful military aggression intentionally planned and perpetrated by the occupying power against the civilian population under its occupation.”
UN chief Ban Ki-moon is heading to the region on Saturday in an attempt to bring an end to the hostilities.
Netanyahu said he had ordered the military to be ready for “a significant broadening of the ground activity.”