"I don't know if the parliaments will ratify it... But if they don't ratify it, there is a mechanism. We will probably go to arbitration or an international court and the issue will be settled in a civilised manner," he was quoted as saying in Sarajevo's Dnevni Avaz daily of Friday.
Josipovic said "the tempo isn't the best" in the handling of this issue but voiced confidence that a solution would be found.
He described Croatian-Bosnian relations as very good although plenty remained to be dealt with. "What's important is that all the outstanding issues we have aren't hot, they don't cause base instincts, political problems or prevent cooperation where we can and must cooperate."
Josipovic said that after July 1, as a new European Union member, Croatia would bring new elements to relations with Bosnia and Herzegovina (BiH) as well as with the entire region.
"It's in our strategic interest that all the countries in the region, notably BiH, join the EU," he said, adding that Croatia would give Bosnia all the necessary support.
Josipovic said Croatia would not act like Slovenia, which made Croatia's road to EU membership conditional on the settlement of bilateral issues. "We are quite determined about that and there's also the Croatian parliament's declaration that we won't mix bilateral issues with the meeting of EU membership requirements. We will abide by that."
Commenting on Bosnia's internal problems, Jospovic said Croatia would not meddle because it had no ambition to be the patron of the Croats living there. Problems can be solved only by an internal agreement and the equality of peoples and individuals is key, he said.