The memorandum of understanding focuses on cooperation in gas pipelines and high-voltage power lines. It was signed at the Three Seas Initiative summit in Ljubljana on Wednesday.

Bratušek said the cooperation between the two neighbours was of great importance, with several projects yet to be completed. "I believe there is no reason for our cooperation not to be successful also in the future."

Szijjarto noted energy security was key to Hungary, and could be improved with the help of better connections with Slovenia. "I think these connections serve interests of both nations."

Bratušek briefed Szijjarto on the rail expansion between Koper and the inland hub Divača, which is important for Hungarian companies which would like to have better access to the Slovenian port.

Hungary had been mentioned by the previous Slovenian government as one of the possible landlocked countries to co-finance the investment.

Bratušek told Szijjarto the decision on whether any country would take part in the project "will be taken shortly, perhaps by the end of the year".

However, "in any case we are committed to complete the project as soon as possible and provide for the shortest path from the sea towards Europe".

Szijjarto said it was important for Hungary that its companies could reach Slovenian port operator Luka Koper in the shortest possible time.

But "the manner in which you realise the project depends on you. If you want us to take part, we'll be there, if not, we won't", he said.

The ministers also discussed roads, especially those on the Slovenian-Hungarian border, which are important for Slovenians in Hungary and Hungarians in Slovenia.

"We're making an effort to enable people to cross the border legally at as many points as possible," said Szijjarto, adding the plan for next year was to complete the missing motorway section between Budapest and Ljubljana.