NATO forces begin their own war games in Ukraine amid fears that an upcoming Russian military drill in Belarus could be a Trojan horse tactic to invade Baltic states.
About 200 people have held an unauthorised demonstration in the Belarusian capital of Minsk to protest their nation's joint military exercises with Russia this month.
Although police in the authoritarian former Soviet republic often harshly break up unsanctioned demonstrations, there were no arrests at Friday's gathering.
The military exercises beginning Sept. 14, have raised concerns among Belarus' beleaguered opposition that Russia could use them to establish a permanent military presence.
Nikolai Statkevich, Belarus' most prominent opposition figure, told the rally that Russia could use the exercises to “use our country as a base for aggression."
The war games, known as "Zapad", or "West", will involve thousands of Russian troops in Belarus, the Baltic Sea, western Russia and the Russian exclave of Kaliningrad.
The Russian exercises have worried NATO despite Moscow's assurances troops would rehearse a purely defensive scenario.
Germany said on Thursday that Russia was planning to send over 100,000 troops to participate in the drill, disputing Moscow's version that only 13,000 Russian and Belarusian servicemen would be involved.
Belarus borders Lithuania and Latvia and is near Estonia. All three Baltic states, which were once part of the Soviet Union, have expressed fears that Russia could try to annex them like it did Crimea from Ukraine in 2014.
The United States has sent a reinforced detachment of fighter planes to police the skies over NATO members Lithuania, Latvia and Estonia during the Russian exercise.
Seven US F-15C fighters landed at Siauliai airfield last month, three more than normally used since the NATO policing mission was upgraded after the Crimean crisis.
The three Baltic states do not operate their own fighter aircraft and rely on their NATO allies for patrols.
Ukraine in the meantime will host its own military drill beginning Sept. 8 till Sept. 23. The exercise will be conducted mainly by NATO member countries, including the United States, the United Kingdom and Turkey.
Russia accuses NATO of building up forces on its frontiers in a manner reminiscent of the Cold War. But NATO says it is protecting the interests of member states bordering Russia who are troubled by Moscow's annexation of Crimea and links to pro-Russian rebels in eastern Ukraine.
The Moldovan government also said on Thursday it has sent 57 servicemen to Ukraine to participate in the military exercises, despite a veto from the country’s pro-Russian president Igor Dodon, who is also Moldova's commander-in-chief.
Dodon argued that Moldova is bound by its constitution to stay neutral, but the Moldovan defence ministry ignored him.
Moldova has been governed by pro-Western governments since 2009 and signed a trade pact with the EU in 2014. Russia retaliated by halting imports of Moldovan farm produce, depriving the country of a key market for its wine, fruit and vegetables.
Relations suffered further this year due to a dispute in March over the treatment of Moldovan officials travelling to or through Russia, and the expulsion of Russian diplomats in May.
In August, Moldova declared Russian Deputy Prime Minister Dmitry Rogozin persona non grata, accusing him of making defamatory remarks about Moldovan government officials.