Mesic told professors and students that the fact that he had arrived at Harvard together with Serbian President Boris Tadic should be interpreted as the proof that the situation in the region was being thoroughly changed.
He recalled that the process of normalising relations between Zagreb and Belgrade had started 10 years ago, and added that the current leaders of the two countries "are interested in full normalisation" for the sake of their respective countries' future and European prospects.
Commenting on the transition through which Croatia has been going, Mesic said that his country has experienced a semi-presidential system with elements of autocracy to grow into a full parliamentary democracy.
In this context he spoke about the present-day Croatia proving its democracy in action and cooperating fully with the International Criminal Tribunal for the former Yugoslavia (ICTY).
The situation evolved from ethnic and religious intolerance to a state of affairs in which ethnically-motivated incidents are sporadic or are consequences of usual criminal acts, he said.
Mesic added that his country is now open to the world and to the notion that it is a part of the present-day world, primarily Europe.
"We need Europe also as we would like to become a European Union member state," he said.
The president said that in the past Croatia's foreign policy used to be Eurocentric, but now his country is open to cooperation with all countries on all the continents, which is why he, as an observer, attended the 15-16 September summit of Non-Aligned Movement in Havana.
Commenting on challenges Croatia will face in the coming years, Mesic mentioned efforts to further contribute to the stability and peace of southeastern Europe, the wish to help in planned constitutional reforms in Bosnia-Herzegovina, the continuation of cooperation with the ICTY and engagement in war crimes trials as well as facing the full truth about the past so that a new architecture of relations can be built in the region.
Mesic also mentioned efforts to counter Euro-scepticism and isolation tendencies.
After his five-day tour of the United States and participation in the 61st session of the United Nations' General Assembly, the Croatian head of state will fly from Boston back to Croatia on Saturday,