I didn’t see any Twilight Zones listed in his filmography. But I did find an old black & white/first season episode of Lost In Space that he did.
1965–1971: Hogan’s Heroes: Colonel Wilhelm Klink
1966: Lost in Space: Bolix: Episode: “All That Glitters”
https://en.wikipedia.org/wiki/Werner_Klemperer#Filmography
Not Werner Klemperer, but someone I’ve seen in other movies. Was thinking Gert Frobe, who played “Auric Goldfinger”, maybe not.
And don’t forget the alien, who was played by Richard Kiel. He played “Jaws” in the James Bond movie “Moonraker”
The gentleman playing the Russian Ambassador in the TZ episode was Theodore Marcuse. He was a character actor who appeared in a number of productions. Notably, he was in a Star Trek episode, “Catspaw.” Sadly, he died in a traffic accident in Hollywood a month after it aired (Nov 1967) at 47.
https://en.wikipedia.org/wiki/Theo_Marcuse