The meeting of Bucharest Nine in Warsaw

President of Slovakia Andrej Kiska, Latvian President Raimonds Vejonis, President of Lithuania Dalia Grybauskaite, Polish President Andrzej Duda, President of Romania Klaus Iohannis, President of Hungary Janos Ader, President of Estonia Kersti Kaljulaid, Czech Speaker of the Chamber of Deputies Radek Vondracek and President of Bulgaria Rumen Radev attend the Poland's Independence 100th anniversary celebrations at the Belvedere Palace in Warsaw, Poland on 8 June 2018. Heads of States of Bucharest Nine countries, NATO's eastern flank countries (Poland, Romania, Estonia, Lithuania, Latvia, Slovakia, Hungary, Czech Republic and Bulgaria) meet in Warsaw to disscuss security issues in region and to adopt joint declaration for the upcoming NATO Summit in Brussels in July 2018. (Photo by Mateusz Wlodarczyk/NurPhoto via Getty Images)