Minister for Foreign Affairs Dermot Ahern will meet Vatican representatives in Rome tomorrow.
He will discuss proposed reforms to the United Nations as part of his work as special envoy to UN secretary general Kofi Annan.
Mr Ahern will also visit the tomb of Pope John Paul II, on the visit, where he will also meet with members of the Italian Government.
He will then travel to San Marino, which is also a member of the UN.