Prime Minister Benjamin Netanyahu says Israel will "go to the end, to victory" despite "international pressures".
His foreign minister says the war in the Gaza Strip will continue "with or without international support".
Eli Cohen says a ceasefire "at the current stage" would be a "gift to the terrorist organisation Hamas".
The UN General Assembly on Tuesday overwhelmingly adopted a non-binding resolution demanding a ceasefire in Gaza.
And US President Joe Biden has said Israel was starting to lose global support over its "indiscriminate bombing" of Gaza.
Meanwhile, an overnight storm has worsened the conditions for hundreds of thousands of Palestinians who have fled their homes.
Many are in makeshift shelters or sleeping rough.
Hamas broke through Israel's heavily guarded perimeter on 7 October, killing 1,200 people and taking 240 hostages - some of whom were released during a brief truce.
The Hamas-run health ministry in Gaza says 18,600 people have been killed and 50,000 injured in the enclave since the start of the war.
