The visit took place a day after Salyukov was named as one of the deputy commanders of Russia's military operation in Ukraine in the latest of a series of reshuffles.

Russia and its close ally Belarus have beefed up their joint military grouping in Belarus and plan to hold joint aviation drills there from next Monday.

The exercises form part of a pattern of activity that has prompted Ukraine to warn that Russian President Vladimir Putin may try to use Belarus to launch a new ground invasion of Ukraine from the north.

Belarusian leader Alexander Lukashenko allowed Putin to use his country as one of the launchpads to invade Ukraine last February, when Russian forces were beaten back in an attempt to take the capital Kyiv.

Military analysts say Russia has also used Belarusian facilities to train up newly mobilised soldiers who were called up last September to boost its forces in Ukraine.

However, Belarus has not sent its own troops into Ukraine in support of Russia's "special military operation" there.

(Reporting by Reuters; Editing by Gareth Jones)