The arbitration agreement stipulates that oral hearings are closed, but the Foreign Ministry plans to ask the government to change the agreement. Croatia agrees with the move in principle, Erjavec said.

This would require renewed ratification of the arbitration treaty by both countries. If everything goes according to plans, oral hearings could be held in June, according to the minister.

While the border dispute has been delegated to the international ad hoc tribunal, the two countries are still at odds over Yugoslav-era deposits held in the Zagreb branch of Ljubljanska banka (LB).

Croatia has indicated it would make sense to resolve this issue with arbitration as well, but Erjavec rejected this possibility as "out of the question".

Croatia only wants to resolve its claims to LB in arbitration, not claims LB has to Croatian companies, he said.

Erjavec has criticised Croatia after recent rulings against LB and NLB at a Zagreb court that he has said are unenforceable in Slovenia and in breach of the 2013 agreement on LB savers.

He acknowledged today that bilateral relations have "cooled down significantly" as a result, saying Slovenia feels "double-crossed" with the "new interpretation" of the 2013 agreement.