Duda's top foreign policy aide, Jakub Kumoch, told public broadcaster Polish Radio the meeting would focus on the directions for Europe's development and how to strengthen the international standing of the European Union.
"The fact that the Polish head of state will be taking part in the Arraiolos Group get-together shows that Poland sees itself as an indispensable part of a united Europe," Kumoch said.
"After Brexit and the 2015 migrant crisis, there are some differences of opinion, but it is vital that we preserve the EU and its strength, and Poland wants to take an active part in this discussion," he added.
On Tuesday, the first day of the visit, the Polish presidential couple will lay a wreath at the grave of St. John Paul II, in Vatican City's St. Peter's Basilica.
Later in the day, at a ceremony in the Polish embassy in the Vatican, Duda will award a state decoration to a high-ranking papal official, Archbishop Jan Romeo Pawłowski.
On Wednesday, Poland's president is set to attend the Arraiolos Group summit, where he will meet with his counterparts from Italy, Bulgaria, Germany, Estonia, Ireland, Greece, Croatia, Latvia, Hungary, Malta, Austria, Portugal, Slovenia and Finland, public broadcaster Polish Radio’s IAR news agency reported.
Two plenary sessions have been scheduled at the Rome get-together: on the road towards strategic autonomy for the EU and on post-pandemic growth, according to officials.
The Arraiolos Group brings together heads of state from EU member countries that have parliamentary rather than presidential models of government. Its meetings are held approximately once a year.
The group is named after the small Portuguese town where the first such meeting took place in 2003.