UN Secretary-General Ban Ki-moon told Israel's prime minister on Friday he was disappointed that a Security Council resolution calling for a ceasefire in Gaza had so far been ignored.
In a telephone call to Prime Minister Ehud Olmert, Ban "expressed disappointment that the violence is continuing on the ground in disregard of yesterday's Security Council resolution," UN spokeswoman Michele Montas said.
Olmert earlier dismissed the resolution calling for an "immediate and durable" ceasefire in the two-week-old war as "unworkable" and warplanes and tanks continued to pound the Palestinian enclave.
Officials of the Hamas Islamist movement that runs Gaza said they were weighing the UN resolution but objected that they had not been consulted. Israel said Palestinian militants continued to fire rockets at Israeli territory.
Senior UN officials have no direct contacts with Hamas but Montas said Ban would "definitely" convey the same message to the militant grouping indirectly. She declined to say what channels he would use.
UN humanitarian affairs chief John Holmes earlier said it was "extremely disappointing" that a ceasefire had not taken hold in Gaza. "It is a reasonable expectation on our part that the parties should comply with that resolution and I hope they will do that in the very near future," Holmes told reporters.
"What we still desperately need is a full, lasting ceasefire so that we can do what we need to do to protect civilians because ... civilians are not safe anywhere in Gaza until there is a full ceasefire."
The resolution was the result of lengthy haggling between Western and Arab states. It was passed by 14-0 in the Security Council, with the United States abstaining.
Apart from a ceasefire, it also called for the reopening of border crossings into Gaza and for the unimpeded distribution of aid in the territory.