Apart from Josipovic other heads of government or state are arriving in Rome on this occasion at the invitation of Italian President Giorgio Napolitano. Some of those guests are U.S. Vice president Joe Biden, Russian President Dmitry Medvedev, UN Secretary-Genera Ban Ki-moon, European Council President Herman van Rompuy, Spanish King Juan Carlos, German president Christian Wulff as well as presidents, Shimon Peres of Israel, Abdullah Guel of Turkey and Hamid Karzai of Afghanistan.
The ceremonies start with a military parade with more than 5,000 soldiers.
Some 2,500 police officers will be deployed for security reasons.
After the parade, a reception and concert will be held.
Josipovic and Napolitano are expected to hold a bilateral meeting in Zagreb soon this summer.