The Israeli military has estimated accomplishing that task, already into its fourth week, will take several more days.
Mr Netanyahu said: "We are determined to complete this mission, with or without a ceasefire.
"I won't agree to any proposal that will not enable the Israeli military to finish this important task, for the sake of Israel's security."
The Israeli military has called up an additional 16,000 reservists. A military source said they would relieve a similar number of reserve soldiers being stood down.
Gaza officials say at least 1,372 Palestinians, most of them civilians, have been killed and nearly 7,000 wounded.
Fifty-six Israeli soldiers have been killed in Gaza clashes and more than 400 wounded. Three civilians have been killed by Palestinian shelling in Israel.
UN Secretary-General Ban Ki-moon strongly condemned the deaths of at least 15 Palestinians among thousands sheltering at a UN-run school on Wednesday. The UN said its initial assessment was Israeli artillery shells hit the facility.
Israel said its forces were attacked near the school and had fired back.