VILNIUS - NATO will closely follow Russia's military exercises near the Baltic countries' borders, including its joint drills with Belarus and China, the Alliance's secretary general said in Lithuania on Tuesday.

Jens Stoltenberg called for transparency at Russia-China joint naval drills in the Baltic Sea in late June and at Zapad, a major military exercise to be held jointly by Russia and Belarus in September.

China's media reported on Monday that three Chinese ships would soon join Russian vessels for drills near St.Petersburg and Kaliningrad. Reportedly, the drills will also include Chinese ship-borne helicopters.

Stoltenberg told reporters in the central Lithuanian district of Jonava that the Alliance was "monitoring all military activities around NATO territory and also close to our territorial waters very closely".

"And, of course, we also follow any exercises and military presence in the Baltic sea from many nations including from China," the secretary general said.

"Nations have the right to exercise their forces, the important thing for us is that this is done in accordance with the international obligations, and rules and arrangements we have for military exercises," he said.

Russia and China have taken turns hosting the Joint Sea drills since 2012, but some observers note that this year's exercise in the Baltic Sea will take place just before US President Donald Trump's visit to Poland.

Stoltenberg said that NATO was also closely following the Zapad drills to be held by Russia and Belarus in September and would raise issues of transparency via the Organization for Security and Cooperation in Europe (OSCE) and at meetings between NATO and Russian officials.

"We are going to follow and monitor the Zapad exercise closely. We call on Russia and also Belarus to do that in accordance with the Vienna document so that we have transparency, predictability related to Zapad 2017," the Alliance's secretary general said.

"We are also working in the framework of the NATO-Russia Council to have more transparency, predictability connected to military posture but also exercises. That is always important but especially important now when we see more military presence along our borders in this region," he said.

Lithuania's military intelligence says that the Zapad scenario will simulate an armed conflict with NATO and warns about possible provocations in the border area during the war games.

Lithuanian President Dalia Grybauskaite said at the joint news conference in the Jonava district that by enhancing its capabilities Eastern Europe, NATO had demonstrated its firm commitment to ensure deterrence and defense, but added that Lithuania would seek even swifter decision-making and greater air defense capabilities in the region