Sergei Chemezov, a close ally of President Vladimir Putin, said that the military operation in Ukraine had prevented an attack on Russia, which he said would emerge victorious from the sanctions imposed by the West.
Putin says the "special military operation" is essential to ensure Russian security after the United States enlarged the NATO military alliance to Russia's borders and supported pro-Western leaders in Kyiv.
Ukraine says it is fighting for its existence and the United States, and its European and Asian allies have condemned the Russian invasion.
Russia's economy is facing the gravest crisis since the 1991 fall of the Soviet Union after the West imposed heavy sanctions on almost the entire Russian financial and corporate system following Moscow's invasion of Ukraine.
"If you glance at Russia's history, almost all of that history Russia has battled with different sanctions, with enemies which encircled her, and she always came out as the victor," Rostec CEO Chemezov told staff.
"Now will be the same."
Chemezov is influential in Russia: he worked as a KGB spy with Putin in East Germany before the 1991 fall of the Soviet Union.
"It won't be a simple life," Chemezov said, according to a video of his remarks sent by Rostec. "The sanctions are rather serious."
But he cast the invasion as a necessary act to prevent a strike against the Russian-backed regions of eastern Ukraine and then on Russia itself.
Chemezov said the sanctions would allow Russia to develop internally.
Rostec is one of Russia's state corporations with interests in weapons, aircraft engineering, radioelectronics, medical technologies, innovative materials.
Its assets include AvtoVAZ, KAMAZ, UAC, Russian Helicopters, UEC, Uralvagonzavod, Shvabe and Kalashnikov.