'We have nothing against Gaza residents, but we are engaged in an all-out war against Hamas and its proxies,' he said.
'This operation will expand and deepen as much as needed,' he said. 'We went to war to deal a heavy blow to Hamas, to change the situation in the south.'
'We will avoid as much as possible hitting civilians while the people of Hamas and other terrorists deliberately hide and operate within the civilian population.'
'We do not want to hit children and women and we will not prevent humanitarian aid' from reaching the besieged enclave, he said.
Mr Barak said that Israel's massive operation was in self-defence to ongoing rocket fire from the Gaza Strip, which has been under Hamas rule since the Islamist movement violently assumed power there in June 2007.
He recalled a conversation with Mr Barack Obama during the US president-elect's June 2008 visit to the Israeli city of Sderot that is regularly targeted by Gaza militants.
The minister quoted Mr Obama as saying: 'had anyone fired rockets against my home while my two daughters were sleeping I would have done everything to stop him and I assume the Israelis would do the same thing.'
'That is what Mr Obama said and that is what we are doing,' Mr Barak said.
Israel unleashed on Saturday a massive bombardment on Hamas targets in Gaza, in a blitz that has killed more than 310 Palestinians and wounded more than 1,400 other, according to medics.
Two Isralis have been killed and some 20 other wounded in retaliatory rocket attacks from Gaza. -- AFP