The court's decision is final and binding, but Croatia withdrew from the proceedings in 2015 and has repeatedly said - as recently as last week - that it will not abide by its rulings.

The Permanent Court of Arbitration found that Slovenia should have "uninterrupted access" to the sea it shares with Croatia, presiding Judge Gilbert Guillaume said, in the case between the European Union neighbours.

The countries have been arguing over a stretch of their sea and land border since both declared independence from the former Yugoslavia in 1991 as it disintegrated into war and broke up.

The dispute, which centres on the bay of Piran, held up Croatia accession to the EU for many years. Only after both parties agreed to arbitration was Zagreb granted entry to the bloc in 2013.