The Three Seas Initiative is a joint Croatian-Polish project, launched at a meeting in Dubrovnik in the summer of 2016, with the aim of strengthening trade, infrastructure, energy and political cooperation in the area between the Adriatic, Baltic and Black Seas.
The initiative is designed as an informal platform to secure political support and action for specific projects. It comprises 12 countries: Croatia, Poland, Hungary, the Czech Republic, Slovakia, Romania, Bulgaria, Lithuania, Latvia, Estonia, Slovenia and Austria. The initiative is strongly backed by the United States and China.
The meeting between Grabar-Kitarovic and Trump will take place before Trump's address in a Warsaw square and is expected to last about half an hour, a source at the Croatian President's Office said.
The meeting will focus on bilateral relations, including defence cooperation, as well as on various agreements which are under preparation, such as the agreement on double taxation avoidance, the agreement on extradition, and the agreement on trade and investment promotion. Also attending will be US Secretary of the Treasury Steven Mnuchin.
The two presidents will also discuss energy and energy security, the source said, adding that progress in building the LNG terminal off the northern Adriatic island of Krk was proof that the Three Seas Initiative was producing results.
Also discussed will be the situation in Southeast Europe, an area of key importance for the long-term stability and security of the entire European Union. The Croatian president will emphasise that in addition to the EU's activities a US foreign policy presence in Southeast Europe is also necessary to underscore the region's European and Euro-Atlantic integration prospects and to jointly respond to challenges facing the entire trans-Atlantic community, the source said.
Grabar-Kitarovic is expected to raise the issue of Croats in Bosnia and Herzegovina, who have been put in an unfavourable situation as a result of changes to the Dayton agreement, and the issue of the border dispute with Slovenia, which Croatia wants to resolve in the spirit of friendship, international law and dialogue, the source added.
The Croatian and US presidents will also discuss the fight against terrorism, uncontrolled migration, and the future of the European Union after the United Kingdom's decision to leave the bloc.
The summit will include the Transatlantic Forum, which will be chaired by the Croatian president and attended by all participating presidents, a panel on the EU's future, and a discussion on cooperation in the implementation of energy, transport and telecommunications projects. A catalogue of over 150 projects worth 45 billion euros has been prepared, including all the member states of the initiative and cross-border projects. The projects are fully harmonised with European strategies.
The most important projects for Croatia are the LNG terminal at Krk and the Rijeka-Budapest lowland railway line.
The Polish government has already built an important LNG terminal on the Baltic coast, and has said that the construction of the Via Carpatia motorway is the most important project at the moment. The motorway would connect Lithuania's port of Klaipeda with Thessaloniki in Greece, passing through eastern Poland, Slovakia, Hungary, Romania and Bulgaria. Currently, there is no north-south motorway in Poland and most of the existing motorways connect Poland with Germany.
The Three Seas Initiative is Croatia's strongest political and economic initiative within the EU. It is primarily aimed at promoting economic cooperation, notably in energy, transport and telecommunications, but it also has a strong political and security dimension.
However, some critics regard it as being anti-European or a counterbalance to Russian and German influence and as a sort of a Trojan horse used by the United States to oppose France and Germany.
The source at the Croatian President's Office denied this, saying that the initiative was not aimed against either Russia or Germany, but aspired to increase the cohesion of Central Europe and consequently of the whole of the European Union and to do away with the divisions into old and new member states, eastern and western Europe, while Russia is considered a desirable partner.
"This message will be strongly emphasised by President Kolinda Grabar-Kitarovic and the White House in Warsaw. That is our contribution to the discussion on the EU's future," the source said.
On Friday, the Croatian president will attend the Global Forum, organised by US think tank the Atlantic Council and the Polish Institute for International Relations. She will have a bilateral meeting with Polish President Andrzej Duda, who recently paid a reciprocal official visit to Croatia. On that occasion, several agreements are expected to be signed between Croatian and Polish companies.