"It is in our common interests to be part of the EU. It is more likely that we will be admitted if we go together and it is better if we joined (the EU) together," Tadic said after meeting Croatian President Stjepan Mesic.
He added that he was glad that Croatia, which is "one step ahead of Serbia", had already started "the process of Euro-Atlantic integration".
Tadic invited Mesic to visit Serbia and the Croat community living there, and expressed readiness to reciprocate the visit.
"Serbs in Croatia should contribute to the Croatian society and state, and the same goes for Serbs in Bosnia-Herzegovina and other countries," Tadic said, adding that minorities should fight for their legitimate interests.
He supported the promotion of economic relations between countries in the region, stating that united they stood better chances in third markets. "The story of Yugoslavia is over, but what remains are strong cultural ties and great economic opportunities," he said.
In order for the countries in the region to normalise their relations and establish new ones, all war crimes indictees must stand trial in The Hague, Tadic said.
Speaking about the possibility of three former JNA officers accused of the Ovcara massacre being tried in Belgrade, Tadic said "we all must face the charges" and that the Serbian judiciary was capable of working in line with European standards.
Earlier in the day, Tadic met Albanian President Alfred Moisiu, with whom he discussed bilateral relations and the situation in Kosovo. The Serbian president said that there were no outstanding issues between the two countries, but that there was the problem of Kosovo. "Kosovo and Metohija are part of Serbia and Montenegro, but we are looking for a viable solution that would be acceptable to all," he said.