Russia tried Wednesday to woo Bulgaria's new government to re-start a project for a new nuclear power plant on the Danube, offering to drop a one-billion-euro ($1.3 billion) arbitration case.

"If Bulgaria undertakes concrete practical steps and not only statements, the arbitration claim for Belene nuclear power plant can be withdrawn," Atomstroyexport vice president Genadiy Tepkyan was cited by state BTA news agency as telling an energy forum in the Black Sea city of Varna.

Russia filed the compensation claim last year at the Paris-based International Court of Arbitration after Bulgaria cancelled a deal with Atomstroyexport to build the 2,000-megawatt nuclear power plant.

Constant price-haggling, severe financial constraints, difficulties attracting investors and safety worries following the Fukushima disaster in Japan had prompted Bulgaria's previous conservative government to pull the plug on the off-again, on-again project.

A referendum in January on reviving Belene failed due insufficient turnout and the outgoing parliament sealed the decision in February.

Bulgaria's new Socialists-backed technocrat Prime Minister Plamen Oresharski, who took office last week, told private bTV television in an interview that he had "a feeling that it would be better to finish the project" rather than losing the arbitration case.

"This is not a project which will begin now but one where much money has already invested -- we would have to pay billions to Atomstroyexport -- so we have to calculate if it would be cheaper to drop or finish Belene," Oresharski said.

"I view Belene as economics not politics. If it has the necessary cost effectiveness it is worth thinking about implementing it, if it does not -- it is not worth it," Oresharski told state BNT television in another interview last week.

The premier ruled out reviving the deal as a state-funded project due to the huge risk for the government finances, fuelling speculation in the media that the project might be restarted as a private one.

Bulgaria's past three governments have failed to find a strategic foreign investor to join in the project.