SOFIA/BELGRADE The United States is deeply worried that Russia's energy deals with Bulgaria and Serbia will tighten its grip on Europe's energy supply and turn into a tool of political pressure, diplomatic sources say.
The two Balkan states signed up to the Kremlin-backed South Stream gas pipeline over the last week. The 10 billion euro ($14.65 billion) project is seen in the European Union as a rival to its Nabucco scheme, designed to ease its dependence on Russian energy.
On Friday Serbian leaders also signed a deal with Russia giving Moscow control of the Serbian oil monopoly.
A confidential Serbian government document obtained by Reuters said Washington was considering using diplomatic channels to express its concern at the deal and point out the shortcomings.
"The U.S. side warned about the political influence Moscow would gain by controlling energy resources in Serbia and the region, and expressed a negative assessment about the economic justification of South Stream," said the transcript of a high level meeting between U.S. and Serbian officials in Belgrade.
"They questioned whether our party took into consideration all strategic effects: possible economic dependency and possibility of political control. They were especially concerned with Bulgaria's decision to join the deal with Gazprom, because it undermines attempts to diversify European gas supplies."
South Stream is proposed by gas export monopoly Gazprom and Italy's Eni to expand Russian supplies to Europe's south.
Western diplomats in Sofia voiced the same concerns, saying the U.S was unhappy to see Russia cementing its presence in the Balkans, possibly gaining a political and strategic foothold as well as an economic one.
U.S. BACKS NABUCCO
A State Department spokesman told Reuters via telephone from Washington that the U.S. continued to view Nabucco as the best scheme to provide energy diversification in Europe.
"Any new energy project in the Eurasia region should contribute to competitive, market-oriented environment for the Eurasian energy and should meet international standards of transparency," the spokesman said.
"For this reason, we continue to view the Nabucco project as the best option for achieving European energy diversification, particularly with regard to providing a direct route to Europe for Caspian and central Asian gas supplies."
Sources in Bulgaria said Washington tried to convince the government in Sofia to back out of the project last week, and Bulgaria's publicly-stated reason for hesitating -- its wish to have 51 percent of the pipeline on its soil -- was a cover.
It finally signed with a 50 percent share.
Washington's worries about transparency have been echoed by analysts who say it is partly politically motivated.
Russia is Serbia's only ally in its bid to block independence for the Albanian-majority Kosovo province, while the EU is likely to recognize the territory within months.
Bulgaria's situation is more complex: it is keen to prove its loyalty to the EU, which it joined in 2007 after years on the waiting list, but it remains dependent for almost all its gas and oil on Russia.
On Friday, the government in Sofia was on the defensive.
"There were comments that Bulgaria had stabbed the EU in the back and had helped the Russian interests," Bulgarian Prime Minister Sergei Stanishev told parliament.
"There have been also statements that this project is an alternative to Nabucco. This is complete nonsense."
(Writing by Ellie Tzortzi; Editing by James Jukwey)