|Italian journalist Giuliana Sgrena seen in car leaving military hospital in Rome|
Mr. Berlusconi Tuesday expressed regret at what he described as unfortunate leaks of reports that the probe will clear U.S. soldiers of blame.
Defense Secretary Donald Rumsfeld said the countries have not yet agreed on a joint report.
U.S. officials Monday said the report will conclude that U.S. soldiers generally followed rules of engagement, when American troops in Baghdad fired on a car carrying the Italian agent and a journalist.
Agent Nicola Calipari was killed and journalist Giuliana Sgrena, who had just been freed after being held hostage in Iraq, was injured.
U.S. officials say the car was nearing a checkpoint at high speed and ignored warnings to slow down. Italian officials dispute this.