Svađe oko partnera, dobavljača gasa i protivponuda od Rusije, koja je osigurala sporazum s partnericom u Nabucco Bugarskom na suparničkom gasovodu zvanom Južni tok, do sad su odlagale napredak ovog projekta EU i SAD.
Quarrels over partners, gas suppliers and counter-offers made by Russia, which secured a deal with Nabucco partner Bulgaria on a rival pipeline called South Stream, have so far delayed progress on the EU/US project.