Russia's president on Friday denounced NATO's plan to hold military exercises in Georgia, calling it a dangerous move that could threaten efforts to improve relations between Moscow and the Western alliance. NATO has said Russia is welcome to join the exercises beginning May 6 and involving 19 other countries. But Russia is vehemently opposed to their being held in Georgia, claiming the former Soviet republic is preparing for aggression against two separatist territories it lost in a war with Russia in August. Russian troops are now stationed the territories, which Moscow has recognized as independent. Russian President Dmitry Medvedev accused NATO of "muscle-flexing" by planning the exercises in the small Black Sea country on Russia's southern border, and suggested they could bring a new chill in relations with the alliance and possible retaliation.