"We have to constructively upgrade (the agreement) so that Bosnia and Herzegovina could prepare for the realisation of its strategic goal, which is accession to the European Union," Mesic was quoted as saying.
Asked by the reporter about the establishment of a third entity in Bosnia, Mesic said that would not be good "because it would ultimately preserve the situation in this country".
He underlined that Bosnia must be organised in a manner which "will guarantee that all three peoples are constituent and all its citizens equal throughout its territory".
"That's primarily a question of the political will of the political forces in Bosnia and Herzegovina. And of the international community's assistance, of course," said Mesic.
Bosnian political leaders are currently in Washington, holding a second round of talks on necessary constitutional changes. The first round was held in Brussels last week.