At the 15th informal meeting of the so-called Arraiolos Group, EU heads of state without executive powers will discuss the importance of the principle of solidarity for deepening the EU and promoting European integration, the Portuguese presidency said in a press release.

The first Arriolos Group meeting took place in Portugal, in the Alentejo town of Arraiolos, in 2003, at the initiative of the then President Jorge Sampaio.

Marcelo Rebelo de Sousa is expected to arrive in Athens on Thursday evening and take part in a dinner hosted by Greek President Prokopios Pavlopoulos for the heads of state at the Acropolis Museum.

The working sessions will take place on the following day, Friday, between 10 a.m. and 6 p.m., in the Zappeion Megaron building, and will focus on "Tackling the economic and refugee crisis effectively" and "Tackling modern security challenges together in the EU and its Member States".

Among the participants of this 15th Arraiolos Group are, besides Marcelo Rebelo de Sousa and Prokopios Pavlopoulos, the heads of state Frank-Walter Steinmeier (Germany), Rumen Radev (Bulgaria), Kolinda Grabar-Kitarovi? (Croatia), Borut Pahor (Slovenia), Kersti Kaljulaid (Estonia), János Áder (Hungary), Michael D. Higgins (Ireland), Sérgio Mattarella (Italy), Egils Levits (Latvia), George Vella (Malta) and Andrzej Duda (Poland).

Next year, the meeting of the Arraiolos Group will take place in Portugal.