Croatia, together with the Visegrad Group and Baltic countries and Romania, has addressed a letter to European Commission President Jean-Claude Juncker asking the Commission to assess whether the North Stream gas pipeline project is in line with European energy legislation and the European Council's conclusions of December 2015.
The letter was signed on the margins of the EU summit in Brussels on Friday by Croatian Prime Minister Tihomir Oreskovic and his counterparts from the Czech Republic, Hungary, Poland, Slovakia, Estonia, Latvia, Lithuania and Romania.
The issue is of particular importance to Croatia because of its plan to build an LNG terminal on Krk island and its overall energy strategy.
Last year Russian energy giant Gazprom and its European partners signed a shareholders agreement on the North Stream 2 project to double the amount of gas that would be delivered from Russia to Germany via the Baltic Sea, bypassing the traditional transit route via Ukraine.
EU countries are divided over the project. The Baltic and Central European countries are opposed to it, while Germany is strongly in favour.