Bulgaria's Prime Minister Boyko Borisov is set to visit Brussels on Thursday, December 4, to meet EU Commission President Jean-Claude Juncker.

The South Stream gas pipeline project, which Moscow is renouncing according to a statement of Russian President Vladimir Putin, will be at the core of their discussions, Juncker was quoted by the Bulgarian News Agency (BTA) as saying.

Juncker has refused to comment on the matter, but the Commission announced on Tuesday it was determined to continue talks on South Stream with member states.

Prior to his meeting with Borisov, Juncker will have to hold talks with some of the Commissioners.

"I will have a say on that matter after these talks and [Borisov's] visit," he was quoted as explaining by public broadcaster BNR.

According to the Commission, the project designed to carry Russian gas across the Black Sea and via Bulgaria to southern and central Europe, bypassing Ukraine, doesn’t  comply with the EU’s Third Energy Package that requires giving access to competitors.

At the same time Putin pointed to Bulgaria's resistance to the project as the reason Moscow was forced to abandon it. Sofia halted South Stream's construction in June after the EU Commission demanded the move over non-compliance with the Third Energy Package and competition issues.

Neither Brussels nor Sofia have so far received documents officially confirming the end of South Stream.

EU Commission spokesperson Anna-Kaisa Itkonen made clear on Wednesday that the EU's executive body is not a party to the South Stream, but is only participating in the dialogue with member states.

Her comments follow Deputy Prime Minister Tomislav Donchev's remarks that the Bulgarian government will insist on a concrete EU response to the developments.

Itkonen reminded the Commission was in no way against the pipeline, but maintained it should abide by EU rules.