In preparation for the NATO summit in Washington in July, high-ranking representatives of several Eastern European NATO states are due to meet in Latvia on Tuesday.
NATO Secretary General Jens Stoltenberg will also take part in the one-day adviser meeting of the so-called Bucharest Nine Group in Riga.
The group includes Poland, Romania, Bulgaria, Hungary, the Czech Republic, Slovakia and the three Baltic States of Estonia, Latvia and Lithuania - in other words, the states along NATO's eastern flank.
The group was founded following the Russian annexation of the Ukrainian peninsula of Crimea in 2014 on the initiative of Poland and Romania.
The next regular NATO summit is due to take place in Washington from July 9 to 11. On the agenda is further support for Ukraine, which is under attack by Russia.
At the same time, the 75th anniversary of the trans-Atlantic defence alliance is to be celebrated. NATO was founded in the US capital in 1949 by the United States, France, Britain and nine other Western states.
Host Latvia, Estonia, Lithuania, Romania, Bulgaria and Slovakia joined NATO on March 29, 2004, while the Czech Republic, Poland and Hungary joined five years earlier on March 12, 1999.
The nine countries in Central and Eastern Europe are concerned about their security in the face of Russia's war on Ukraine and - with the exception of Hungary - are among the staunchest supporters of Ukraine.
