ZAGREB, Croatia (AP) — The prime ministers of Croatia and Slovenia have failed to break a deadlock over an international arbitration ruling in a long-standing border dispute that has led to tensions between the two neighboring European Union countries.

Croatia's Andrej Plenkovic and Slovenia's Miro Cerar disagreed Tuesday over whether the June decision by a Netherlands-based panel should be implemented. It grants Slovenia unhindered access to the Adriatic Sea, and addresses several other unresolved border issues.

Plenkovic has reiterated that Croatia rejects the ruling, but has urged flexibility and proposed further talks for solving the dispute, which stems from the breakup of Yugoslavia in the 1990s.

Cerar has insisted that joint implementation of the international ruling is the only solution for the border dispute. He says Slovenia will go ahead with its implementation.