"We will begin withdrawing 300 men in September," he said, adding that the decision would depend on the security situation on the ground. He said he had discussed the plan with allies and with the Iraqi government; but, he added: "We will have to give confirmation" on the decision.

Berlusconi sought to portray the move as a continuation of existing policy, noting that he had already announced plans to start withdrawing troops. In fact, Italy's stance has been unclear since March when Berlusconi gave conflicting signals about his plan.

His foreign minister, Gianfranco Fini, had most recently indicated that there would be no movement until early 2006.

Yesterday's announcement was bound to prompt criticism that Berlusconi was aiming to deter Islamist terrorists from striking at Italy next. The announcement came amid growing concern in Italy that his government's staunch backing for the policies of the Bush administration had put Rome or Milan next in line for an al-Qaida attack.

Berlusconi warned on Thursday that Italians were "exposed" to terrorist attacks, and yesterday one of his ministers, Roberto Calderoli, said: "It is clear that, after New York, Madrid and London, Italy represents the terrorists' most likely short-term objective."