(ANSA) - WARSAW - ''The crisis between Russia and Ukraine is the biggest threat to security in Eastern Europe since the Cold War. And for this reason Nato's eastern border should be strengthened''. This is what Poland's President Bronislaw Komorowski said in Warsaw today at the meeting attended by the heads of state of the Baltic countries (Latvia, Lithuania, Estonia), the Visegrad Group (the Czech Republic, Slovakia, Hungary than to Poland), Bulgaria and Romania. Komorowski had spoken about this issue over the phone this morning with US president Barack Obama.

According to the heads of state gathered in Warsaw, the issue of strengthening Nato's eastern border will have to be addressed at the next summit of the Organization to be held in Wales in September. According to Poland's President, security must be ensured in all member states. The Russian-Ukrainian crisis, Komorowski said, ''is affecting the European cohesion'', which is granted by ''respecting the territorial integrity'' of each country. (ANSA).