What is Niko's nationality in GTA 4?

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

Roman Bellic in GTA 4 — GTA Guide

Download Niko Bellic of EFLC for GTA 4

GTA IV Customizable Niko Extended mod by LuanJaguar93 file - ModDB

My favourite ever GTA quote (Niko Bellic) what's yours? : r/GTA

Michael Hollick - 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

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

Grand Theft Auto IV (Video Game 2008) - FAQ - IMDb

Hossan Ramzy GTA 4 Characters, Bio & Voice Actor (GTA IV, TLaD & TBoGT)

Download Improved Niko by FoxySkill for GTA 4