Russian Defense Minister Sergei Shoigu resurfaced on Russian state media on Thursday after nearly two weeks out of the public eye, Reuters reported.
Shoigu was seen in a snippet of footage showing him attending a virtual meeting with Russian President Vladimir Putin and others on the country's Security Council.
Russian news agency RIA broadcast the footage after some Russian news outlets noted his prolonged absence from public view.
"The defense minister has a lot on his mind right now. A special military operation is underway. Now is not really the time for media activity," Kremlin spokesman Dmitry Peskov told journalists on Thursday, according to Reuters.
The development comes four weeks after Russia began its invasion into Ukraine, dubbed a "special military operation" by Moscow.
A senior military official from NATO told several news outlets that, based on numbers provided by Ukrainian officials, up to 40,000 Russian soldiers have been killed, taken prisoner, are missing or are injured. As many as 15,000 Russian troops have been killed in the fighting, along with six generals.
Russia is likely to challenge those figures, however, and has not provided casualty estimates in recent weeks.
Before Russia's invasion on Feb. 24, many Western officials projected Ukraine could fall within a matter of days. However, a month into the fighting, Moscow has seized only a handful of smaller cities and Russian advances have faced fierce pushback on the ground and in the sky.
Defense Secretary Lloyd Austin offered a bleak assessment last week of how Russian forces were progressing in Ukraine, saying that Moscow had "struggled with logistics" and made "missteps."
"I don't see, you know, evidence of good employment of tactical intelligence. I don't see integration of air capability with a ground maneuver," Austin told CNN's Don Lemon.
"And so there are a number of things that we would expect to have seen that we just haven't seen, and the Russians really have had some ... problems. So, many of their assumptions have not proven to be true as they entered this fight."