Mesic delivered a talk at the Euroasian Strategic Research Institute, the country's most respected scientific institution.
"The border of Europe is not this or that river or mountain, its border stretches as far as European values, tradition and culture do," the Croatian president told an audience of some 200 Turkish politicians, intellectuals and journalists.
Earlier in the day, during talks with Turkish President Ahmet Necdet Sezer, Mesic supported the aspiration of this predominantly Muslim country with a population of over 73 million to join the European Union.
Speaking of Croatia's progress to EU and NATO membership, Mesic said that both Croatia and Turkey were examples that Europe was not closing its door to new members, and added that this also applied to Croatian neighbours Serbia-Montenegro and Bosnia-Herzegovina.
Mesic underlined that the opening of EU membership talks with Croatia was a positive signal to the entire region.
The Croatian president also met Turkish Parliament Speaker Bulent Arinc and former President Suleyman Demirel, who had played an active role in resolving the crisis in the former Yugoslavia and the Croat-Muslim conflict in Bosnia-Herzegovina.