Mr Berlusconi insisted there was no timetable for withdrawal and said any decision would be made together with Italy's allies.
The attack, which made it Italy's deadliest day in the conflict, wounded another four troops.
"We are all convinced it's best for everybody to get out soon," Mr Berlusconi said.
Mr Berlusconi said Italy had already planned on bringing home some 400-500 soldiers, referring to extra troops who had beefed up Italy's contingent for the Afghan elections.
"We're obviously anxious to bring our boys home as soon as possible," he said.
Italy has about 2,800 soldiers in Afghanistan.
His comments came as the new head of the British Army, General Sir David Richards, warned defeat for the international coalition would have an "intoxicating impact" on global extremists.