Simona Drenik

Slovenia on Friday submitted to the European Commission a letter of complaint against neighbouring Croatia for its refusal to abide by an arbitration court ruling on a border dispute in the Adriatic Sea.

After months of rows and cancelled meetings, Slovenian Prime Minister Miro Cerar is visiting Zagreb on Tuesday to meet his Croatian counterpart Andrej Plenkovic in the hope of moving forwards towards a resolution of the territorial dispute between the two states.

Slovenian Prime Minister Mirko Cerar on Thursday said that he was cancelling his visit to Zagreb after his Croatian counterpart, Andrej Plenkovic, told the UN in an address that Slovenia had "compromised" international arbitration of their dispute over the Piran Gulf.

Ahead of an announced decision of the Permanent Court of Arbitration in The Hague on Thursday on the dispute over territorial waters between Croatia and Slovenia, Croatia has made it clear it will not accept the ruling.

Croatian Prime Minister Zoran Milanovic scheduled a meeting for Monday with the heads of all 13 parliamentary groups to update them after Zagreb said last week that it may pull out of international arbitration with Slovenia over the Piran Gulf following revelations of secret conversations between a judge and the Slovene representative.

The arbitation process between Slovenia and Croatia in the Hague over the waters of the Piran Gulf in Istria was in doubt on Friday, after the Slovene judge on the panel and the Slovenian representative resigned - and after Croatia warned it may back out of the process entirely.

Hearings at the Hague-based court for the resolution of international disputes began on Monday with Croatia presenting its case, as Zagreb and Ljubljana attempted to settle a dispute that has continued since they both became independent from the former Yugoslavia.