"We aren't excluding any options [concerning South Stream], because we have not received the official Russian position," Plevneliev said in an interview with the Prague newspaper Lidove noviny.
Plevneliev also indicated that the Bulgarian government is proceeding with the preparatory work for the project's implementation and expressed hope that construction of the gas pipeline would be resumed.
"I hope that the project will eventually get all the necessary construction permits. The Bulgarian position is clear – the project can be implemented only on condition that it will be in compliance with the legal standards of the EU," Bulgarian President emphasized.
The announcement comes at a time when Bulgaria is highly dependent on Russian energy supplies, with about 90 percent of its natural gas coming from Russia.
On December 1, 2014, Russian President Vladimir Putin announced that Russia was abandoning the South Stream gas project.
Among the reasons cited by the president for the project's cancellation, included the "non-constructive" position of the European Commission. Brussels claimed that the project violated the European Union's Third Energy Package, which prohibits the companies simultaneous owning both the gas and the pipeline through which it runs.
On the same day, the head of Russia's energy giant Gazprom Alexei Miller confirmed that the South Stream project had been abandoned, saying that it would be replaced by an alternative pipeline routed through Turkey.
The so-called Turkish Stream will deliver Russian gas to Turkey and customers in South Europe by means of a transit hub on the Turkish-Greek border.