"We've already done enough," he said during a cabinet meeting, according to Italian news reports.
France and Britain have been pressuring Nato allies to step up air bombing missions against Libyan leader Muammar Gaddafi's forces. France was the first to bomb the Libyan military last month, before a UN mandate to use force to protect civilians.
Italy has contributed eight aircraft to the mission but only for reconnaissance and monitoring operations, according to the government which said the aircraft will not open fire.
That policy won't alter, defence minister Ignazio La Russa told reporters in Rome following the cabinet meeting.
"We're not going to change," he said.
The statements are a change of tack from an interview with daily Il Sole 24 Ore published on Thursday when Italian foreign minister Franco Frattini said his government might be convinced by rebels to use lethal force against Libya's military.
"If the Libyans give us strong arguments we will see, the government will decide," he said.
Libya was an Italian colony from 1911 to 1943 and Italy is the North African country's biggest trade partner.
Berlusconi had forged close ties with Gaddafi, going so far as to kiss his hand during a visit to Libya.
Earlier this week, at a dinner with members of the foreign press in Rome, Berlusconi also said he was ready to resign last month when the United Nations approved a measure to bomb Libyan military forces.
"But everyone asked me to not do it, so I stayed in my post," the Wall Street Journal reported.