Five Italian naval vessels have left for Lebanon, carrying nearly 2,500 troops to join the UN peacekeeping force deploying in the south.
The Italian task force has helicopter support for the troops
In the first phase, 980 of the Italian troops will go ashore.
The aircraft carrier Garibaldi was accompanied by three landing craft and a patrol boat. They left the ports of Brindisi and Taranto on Tuesday.
The ships are expected to reach the Lebanese port of Tyre on Friday, the AFP news agency reports.
The Italian contingent will be the largest in the UN force, which is to be expanded from 2,000 to 15,000 under the UN-backed ceasefire.
UN TROOP PLEDGES
France - leadership and 2,000 troops
Italy - 2,000 - 3,000 troops
Bangladesh - two battalions (up to 2,000 troops)
Malaysia - one battalion
Spain - one mechanised battalion
Indonesia - one battalion, an engineering company
Nepal - one battalion
Denmark - at least two ships
Poland - 500 troops
Finland - 250 troops
Belgium - 302 troops, later rising to 392
Germany - maritime and border patrols but no combat troops
Norway - 100 soldiers
France will command the force initially, with Italy assuming command in February next year.
Italian Prime Minister Romano Prodi and Defence Minister Arturo Parisi spoke to the troops aboard the Garibaldi in Brindisi before they left.
"It is a delicate mission, of enormous historical importance," Mr Prodi said, adding that the conditions of the deployment were "clear and unequivocal".
Israel has reiterated that it will not finally withdraw from southern Lebanon until the UN peacekeeping force is deployed.
European Union states have pledged up to 7,000 troops for the force.
Mr Prodi said Italy had returned to play an important role on the international stage.
The Italian Foreign Minister, Massimo D'Alema, has said the new UN mission in Lebanon marks the end of the unilateralism that has marked American foreign policy since the 11 September 2001 attacks.
He told the Milan-based newspaper Corriere della Sera that the new mission marked the return of the UN and Europe to centre stage.