SOFIA – President Vladimir Putin will seek Bulgarian assent to an ambitious scheme securing Russian expansion of gas deliveries into Southern Europe when he visits Sofia on possibly his last foreign visit before stepping down. The 10-billion-euro South Stream, proposed by Russian gas export monopoly Gazprom and Italy’s Eni, is Moscow’s challenge to the rival Nabucco plan to pipe Central Asian gas to the EU and curb European dependence on Russian gas. Failure to reach a deal on Bulgarian participation could be a major upset to Putin, who will be accompanied by the man he favors to succeed him as president after a March election, First Deputy Prime Minister Dmitry Medvedev. After a week of intensive talks, Sofia has not yet reached agreement with Moscow over its role, raising doubts over prospects to have the deal signed during Putin’s visit, beginning today, Bulgarian officials said. Russia’s Interfax news agency quoted an unnamed Kremlin source as suggesting Western interference was to blame for hesitation by the former Soviet ally. «We see attempts… to dictate to the Bulgarians,» the source said. «As soon as we achieve progress in bilateral relations, all sorts of US State Department officials appear telling them, ‘Do you really need this?’» «We also treat as negative (the fact) that some of the actions are initiated not by Sofia, not because of its national needs or specifics of Bugaria’s economy or politics,» he added. Bulgarian officials say they want a majority stake in the South Stream pipeline to be going through Bulgaria, something Moscow is unwilling to agree to. «Bulgaria wants to protect its national interests and those of the European Union,» a senior government official told Reuters. «Both sides have to make concessions.» Breakthrough possible? The pipeline, which would carry 30 billion cubic meters of gas under the Black Sea, would re-emerge on the Bulgarian coast to continue through one of two routes. It could pass through Greece and reach Italy, or pass through Romania, Hungary, the Czech Republic and Austria before arriving in Italy. Bulgarian Foreign Minister Ivailo Kalfin said, after the government discussed the project at a closed-door meeting, that talks were continuing today. Asked whether Sofia could sign a South Stream deal today, Kalfin said, «We are not ready for that for now.» But the senior government official said a breakthrough was still possible today. «We will work hard to have problems sorted out, and there is still a chance,» a source in the Russian delegation said. Brussels has made Nabucco a key plank in its efforts to diversify gas supplies away from Russia after a political dispute between Moscow and Kiev in 2006 cut off exports via Ukraine. Russia supplies a quarter of the EU’s gas. Putin told Bulgarian daily Trud that there was no clash of interests in the South Stream deal with Sofia. «Projects like… South Stream are fully in line with Russia’s long-term interests and those of our European partners, including Bulgaria,» he said.