Moscow said 200,000 personnel will take part in the week-long Zapad-2021 military exercise in Belarus, western Russia and the Baltic Sea.

The defence ministry released footage of coordinated drills with rows of Russian warships firing artillery, military jets flying in formation and columns of tanks advancing over rugged terrain.

On the eve of the exercise, Russian President Vladimir Putin said they were "not directed against anyone".

His isolated Belarus counterpart, Alexander Lukashenko, said the countries are "not doing anything that our opponents are not".

The strongman pair -- both in power for more than two decades -- spoke in the Kremlin on Thursday after agreeing to deepen the integration of their ex-Soviet countries, including militarily.

The exercises have worried the EU's eastern flank that borders Belarus and Russia, which has recently accused the Minsk regime of purposefully sending migrants over their borders.

Poland has introduced a state of emergency along its eastern border, the first time the measure has been used since the fall of Communism.

Ahead of the drills, Polish Prime Minister Mateusz Morawiecki warned of possible "provocations" and said the exercises were one reason Warsaw introduced the state of emergency.

Warsaw's Defence Minister Mariusz Blaszczak told Polish media on Friday that the country was prepared for possible "borderline incidents".

The country has deployed troops to build a barbed wire fence along the border after a growing number of migrants -- mostly from the Middle East -- have tried to cross into it from Belarus.

- Closer military ties -

Brussels suspects the influx is being deliberately engineered by Lukashenko as a form of retaliation against increasingly stringent EU sanctions on his regime.

Putin on Thursday said EU leaders had asked him to intervene, but the Russian leader said Moscow had "nothing to do with it".

He said Poland should take in any Afghan citizens trying to cross its border.

"You can blame anything on Belarus, but at least take in the Afghans," the Russian leader said.

Putin accused the EU of having no problem in talking to the Taliban, but not to Lukashenko, who is in power "as a result of a vote, whether you like it or not".

Putin has extended a helping hand to Lukashenko since unprecedented protests against him last year over an election widely seen as rigged.

The Kremlin chief has long sought political integration with Belarus.

On Thursday, the Russian leader said he had discussed "building a single defence space" with Belarus and agreed on a range of economic policies integrating the two countries.

Russia's Prime Minister Mikhail Mishustin went to Minsk on Friday to discuss the plans with his Belarus counterparts.

The Kremlin said on Friday that Putin would visit Belarus in November.

Lukashenko said Belarusians had no need to worry and that Russia would not "swallow" his country.

Russia and Belarus sought to present a unified front in their confrontation with the West.