Šarec told the press in the afternoon that in the meeting with Juncker, he had reiterated the country's position on the Slovenia-Croatia border arbitration decision, and acquainted the European Commission president with the history of the arbitration issue.

"Today we cannot talk bout bilateral meetings or anything else of that sort. Today we have a decision on the table, made by the arbitration tribunal, and we can only discuss how we are going to implement it in practice," he added.

Asked whether he had asked Jucker why he had not reacted to the opinion of the Commission's legal service favouring Slovenia's position, Šarec said that he was interested only in the future - how the decision will be implemented.

He stressed that he had repeated Slovenia's position and that Juncker had heard it, and not for the first time.

Asked about expectations, the prime minister said that "it would not be too wise to talk about any expectations". "Our duty is to express our opinion clearly and loudly. And then we will see what happens," he added.

The European Commission's press service meanwhile said that Juncker had welcomed Slovenia as an important, responsible and reliable partner for the future of Europe.

Šarec and Juncker agreed that it was important to protect the external borders of the EU and that controls on the internal borders should be eliminated gradually to return to free movement of people.

With regard to the border arbitration decision, Juncker repeated the Commission's position and its readiness to help in the process of its implementation.

The Commission expects Slovenia and Croatia to implement the decision, but has failed to launch any concrete initiatives for this to happen. It has stressed that the countries should find a friendly solution for its implementation.

Šarec said that he would also express Slovenia's position clearly at Friday's meeting with German Chancellor Angela Merkel in Berlin. He said that Germany was familiar with the issue and that he expected that Slovenia's position would be endorsed.

The meeting with Tusk lasted longer than the scheduled half hour, with the Slovenian side describing it as very good and concrete, with an emphasis on the preparations for the next week's EU summit and Brexit.

Tusk tweeted after the meeting that he was happy to receive Šarec on his first visit to Brussels and that they had talked about Brexit, the Western Balkans and the upcoming summit.

Tusk's press service added that the meeting had also discussed internal security, migrations, populism, Russia and the developments related to the Slovenian-Croatian border dispute.

Šarec also told the press after meeting Juncker and Tusk that the first visit was a signal sent to the world, adding that he had picked Brussels as Slovenia was an EU member which was aware of its rights and obligations.

He described the atmosphere and impressions from Brussels as good. "I can describe all today's meetings as very constructive and positive."

Šarec emphasised that he and Tusk "clicked immediately" and that they shared the same values and views of how problems should be solved.

The prime minister also met European Commission Vice-President Andrus Ansip, the commissioner for digital single market, and the eight Slovenian MEPs.

The meeting with Ansip discussed market digitalisation, with the vice-president presenting some interesting proposals and ideas, Šarec said, adding that Ansip was also a strong supporter of the border arbitration decision.