What is Niko's nationality in GTA 4?

Given his European origins, some GTA 4 players remain confused about Niko Bellic’s nationality.

Niko Bellic, GTA Wiki

Niko Bellic V.S. Steve Fox - Tekken 8 by FBIRancher7590 on DeviantArt

Grand Theft Auto IV - Grand Theft Wiki, the GTA wiki

Niko Bellic - Wikipedia

An old Tweet but I thought it'd be interesting to share nonetheless. Niko's voice actor confirming that he's Serbian : r/GTAIV

What happened to Niko?

Rockstar confirmed Niko was Serbian a few years ago - GTA IV - GTAForums

Niko Bellic May Return in Grand Theft Auto V Or Maybe not?

Find an Actor to Play Dimitri Rascalov in Grand Theft Auto IV ( Prime) on myCast

Niko Bellic, The Grand Theft Auto IV Chain Story Wiki

Niko Bellic-GTA IV : r/StableDiffusion

So what is the nationality of Niko? - Page 4 - GTA IV - GTAForums

Niko Bellic Evolution in GTA Games (Cameos and References)

Roman Bellic in GTA 4 — GTA Guide