The visit will begin with Pahor receiving his Italian counterpart at Europe Square which connects the border towns of Nova Gorica in Slovenia and Gorizia in Italy.

The square was the site of the main ceremony celebrating Slovenia's entry into the EU on 1 May 2004.

Presidents Pahor and Napolitano are to stroll the square and greet passers-by before meeting representatives of the Slovenian minority in Italy and the Italian minority in Slovenia.

The visit will also be dedicated to remembering the 100th anniversary of the start of the first world war, as part of which the presidents will visit the Sveta Gora hill near Nova Gorica.

There they will lay a wreath at a monument honouring dead Slovenian soldiers and unveil "a bench of peace" to offer visitors a place to remember and reflect on the horrors of war.

Napolitano is returning a visit which Pahor paid to Italy in May of this year.

Already on Sunday evening, the two presidents attended a concert in Italy's Redipuglia dedicated to remembering the start of WWI.