He said the decision on when forces would go into the Palestinian enclave, controlled by the Islamist movement Hamas, would be taken by the government's special war cabinet, which includes the leader of one of the centrist opposition parties.
"We have already killed thousands of terrorists and this is only the beginning," Netanyahu said.
"Simultaneously, we are preparing for a ground invasion. I will not elaborate on when, how or how many. I will also not elaborate on the various calculations we are making, which the public is mostly unaware of and that is how things should be."
Israel has carried out days of intense bombardment of the densely populated Gaza Strip following the October 07 Hamas attack on Israeli communities that killed some 1,400 people. More than 6,500 Palestinians have been killed in the bombardments, according to Gaza's health ministry.
Netanyahu, who has so far not taken responsibility for the security failures that led to the Hamas attack, said all involved would be called to account.
"The scandal will be fully investigated," he said. "Everyone will have to give answers, me too. But all this will happen only after the war."
Earlier, citing US and Israeli officials, the Wall Street Journal reported that Israel had agreed to delay the invasion of Gaza for now, so the United States could rush missile defences to the region.
Reuters reported on Monday that Washington advised Israel to hold off on a ground assault and is keeping Qatar - a broker with the Palestinian militants - apprised of those talks as its tries to free more hostages and prepare for a possible wider regional war.
