Slovenia's outgoing President Borut Pahor, who arrived in Zagreb on Monday on a a two-day visit, said he was 'certain' that the arbitration agreement on the Slovenia-Croatia border 'would be applied sooner or later.'

“I am positive that the provisions of the border arbitration agreement will be applied sooner or later, it is not necessary to have them implemented overnight. Those provisions have no alternative,” Pahor said at a joint news conference with his host, Croatian President, Zoran Milanovic.

Pahor, a former Social Democrat leader, served as Slovenia’s  Prime Minister from 2008 to 2012.

During his premiership, Slovenia blocked Croatia’s EU membership over a long-standing border dispute. However, in 2009, the two countries reached a deal on launching arbitration proceedings for their border dispute.

In 2015, Croatia, which entered the EU in 2013, withdrew from the arbitration process, citing the discrediting of the process when Slovenia tried to influence some of the judges. Although the judges were later replaced, Croatia refused to return to the table. The arbitration ruling is recognized by Slovenia but rejected by Croatia, whose governments have called on Slovenia to get back to resolving the issue bilaterally.

Slovenia later insisted on the implementation of the arbitration ruling as a precondition for Croatia’s admission to the Schengen Area.

Pahor said on Monday that he intentionally chose Croatia as the last destination for his official visits in his capacity as the head of state. He explained that during his term as president he had attached ‘the greatest attention’ to Croatia of all the other neighbors of Slovenia. Pahor said that he had over 55 meetings with three former Croatian presidents during his decade in office: Ivo Josipovic, Kolonda Grabar-Kitarovic, and the incumbent Zoran Milanovic.