Russian forces have begun their biggest military exercise in the Caucasus since a war with Georgia last year.
More than 8000 troops are taking part in manoeuvres near the Georgian border, which Georgia has called "a pure provocation from Russia".
Last month NATO angered Russia by staging exercises in Georgia itself.
Analysts say the latest exercises are a clear warning from Moscow to the West.
The BBC reports military experts in Moscow say the message is that the Caucasus is still part of Russia's sphere of influence.
The exercises involve 8,500 military personnel, 200 tanks, 450 armoured vehicles and 250 pieces of artillery.
They are due to end on the day US President Barack Obama arrives in Moscow for a summit with Russian President Dmitry Medvedev.
Russia maintains heavy military presences in Georgia's two breakaway regions of South Ossetia and Abkhazia and has recognised them as independent.
Meanwhile, 130 UN observers who have been monitoring the administrative boundary between Abkhazia and Georgia will leave in the next three months.
The International Crisis Group last week warned that the pullout by the UN and OSCE would fuel tensions.