Shoigu, a close ally of President Vladimir Putin, reportedly last appeared in public on March 11 despite his leading role in Russia's military operation in Ukraine.

Some Russian media reports have speculated that he could have health problems.

Kremlin spokesman Dmitry Peskov sought to quell such rumours however, telling journalists: "The defence minister has a lot to take care of at the moment. There is a special military operation going on."

"This is not the moment for media activity," he added.

The Kremlin said Thursday that Shoigu had informed Putin on the latest developments in Ukraine.

The defence minister, 66, usually features regularly on state television broadcasts and has been filmed going on expeditions into the Siberian wilderness with Putin.

Russian officials' absences often prompt rumours of illness, due to the fact that the authorities are reluctant to release such information even if true.

Rumours have swirled on several occasions when Putin has disappeared from public view for a week or more.

"We would be bored if there were no rumours," he said in 2015 after a 10-day absence.