The information was confirmed by the Bulgarian Ministry of Economy and Energy. In Buglaria, Miller will hold talks with PM Boyko Borisov and Minister of Economy and Energy Traicho Traikov.

Bulgaria has had an uncertain stance on South Stream, which has led to an activizing on the part of the Russian side. Just Monday Russian press characterized Buglaria as the "problematic" country for South Stream.

Bulgaria has been committed to the execution of the EU-sponsored Nabucco gas pipeline project, which is widely seen as rival to South Stream.

Nevertheless, in July Russia secured commitment on the part of Bulgaria for South Stream, after visits by first deputy-PM Viktor Zubkov and energy minister Sergey Shmatko.

Tags: Gazprom, Alexei Miller, natural gas, South stream, Traicho Traikov