"Full membership of the EU is the most important foreign policy objective for all relevant forces in Croatia," Mesic said at the beginning of his lecture.
Mesic divided Croatia's development from the early 1990s to the present day into two sections - historical romanticism and political realism.
He said that the process of European unification could not be completed without the admission of not only Croatia, but of all countries in the region.
The president said that Croatia was aware that Europe was not perfect and mentioned problems with the ratification of the European constitution and the withering away of the welfare state.
In a debate that followed the lecture, Mesic said, among other things, that solving the Kosovo issue should be viewed as completion of the process of creation of new states in the area of the former Yugoslavia.
The chairman of the European Parliament's Foreign Affairs Committee, Elmar Brok of the Christian Democratic Union (CDU), said that Croatia could not formally become a full EU member at present due to restrictions from the Nice treaty. However, he expressed confidence that the completion of talks with Croatia would coincide with Germany's plans to implement the ratification of the European constitution by 2009, which would formally open the door to full EU membership for Croatia.
Brok also underlined the importance of Croatia's role in stabilising the Western Balkans.
We are grateful to Croatia for its subtle policy towards Serbia, he said.
During his visit to North Rhine - Westphalia, which is to last until Thursday, President Mesic will meet a number of top politicians and business people.