Ukraine was to blame for last month's European gas crisis and must bear responsibility for compensating any losses incurred as a result of it, Russian President Dmitry Medvedev said Thursday.
"Financial and legal responsibility lies with Ukraine. Responsibility for any losses rests with them," Medvedev said after meeting Bulgarian President Giorgy Piranov, whose country has demanded compensation for the cutoff of gas supplies from Russia.
The comments hinted at continued strains between Moscow and Kiev over the gas row, which highlighted European dependency on the transit route from Russia through Ukraine.
The gas crisis - which disrupted the supply of gas into Europe for almost two weeks - underscores the need to diversify supply routes, Medvedev said, referring to a Russian plan to build a "South Stream" pipeline under the Black Sea to Europe.
The European Union receives roughly 25% of its natural gas from Russia, and the disruption came amid a bitter cold snap across eastern Europe.
"The main thing, firstly, is creating modern means to resolve such disputes, and secondly, diversification of gas supply. I mean, among other things, implementing the South Stream project," Medvedev said at the Kremlin.
The row between Russia and Ukraine came as relations between Moscow and the West had reached a post-Cold War low after an August war in Georgia.
Diversification of supply is an absolute necessity, Bulgarian President Giorgy Piranov said after his meeting with Medvedev.
"We have no alternatives to a diversification of energy supply," he said.
"Bulgaria wants to assist in the South Stream project and Nabucco, which have become European Priorities," Piranov said, referring to an alternative gas pipeline through Georgia.