BUCHAREST (Dispatches) -- Romania, Turkey and Poland have expressed concern about what they call Russia's "increasing and visible offensive military posturing," near NATO borders.
The foreign ministers of the three NATO members on the eastern flank issued a statement condemning "the repeated violation of NATO airspace, the continued military buildup in Crimea and Kaliningrad" and "continued violation of obligations and commitments on arms control."
Their statement accused Russia of using hybrid tactics that have "serious implications for the regional security and beyond."
Russia on Tuesday launched its largest military exercise since the Cold War, mobilizing 300,000 troops that will also involve thousands of Chinese forces, amid worsening relations with the West.
Romanian Foreign Minister Teodor Melescanu met his Turkish counterpart Mevlut Cavusoglu and Polish Foreign Minister Jacek Czaputowicz in Bucharest to discuss regional security issues.
China and Russia have staged joint drills before but not on such a large scale, and the Vostok-2018 (East-2018) exercise signals closer military ties.
Vostok-2018 is taking place at a time of heightened tension between the West and Russia, and NATO has said it will monitor the exercise closely, as will the United States which has a strong military presence in the Asia-Pacific region.
Russia's Ministry of Defense broadcast images on Tuesday of columns of tanks, armored vehicles and warships on the move, and combat helicopters and fighter aircraft taking off.
In one clip, marines from Russia's Northern Fleet and a motorized Arctic brigade were shown disembarking from a large landing ship on a barren shore opposite Alaska.
This activity was part of the first stage of the exercise, which runs until Sept. 17, the ministry said in a statement. It involved deploying additional forces to Russia's far east and a naval buildup involving its Northern and Pacific fleets.
The main aim was to check the military's readiness to move troops large distances, to test how closely infantry and naval forces cooperated, and to perfect command and control procedures. Later stages will involve rehearsals of both defensive and offensive scenarios.
Russia also staged a major naval exercise in the eastern Mediterranean this month and its jets resumed bombing the Syrian region of Idlib, the last major enclave of terrorists.