Russia did not claim ownership of the moon.
The man who said it was a private contractor, not a government official, and what he said was
// We think that Venus is a Russian planet //
isn’t claiming ownership, it is indicating Russia’s long history of exploring Venus through the Venera missions.
While the Russians were the first to land on Mars in 1971, they have largely ignored it since. NASA has made 10 landings.
The Russians put their energies into Venus exploration.