U.S. Secretary of State John Kerry is in Bulgaria to press the NATO nation to decrease its heavy dependence on Russia for energy.
Kerry arrived in Sofia late on January 14 and planned to explore ideas with Bulgarian officials for diversifying the country's energy supply.
Among those ideas are the possible construction of a natural gas pipeline spur from Greece and moving ahead with a stalled contract with Westinghouse to build a reactor at the country's Kozloduy nuclear power plant, according to U.S. officials.
Bulgaria relies on Russia for 85 percent of its gas and 100 percent of its nuclear power.
Russia's cancellation of the South Stream pipeline, which would have run under the Black Sea to Bulgaria, is making the need for diversification more pressing.
The pipeline was intended to pump Russian gas underneath the Black Sea and through the Balkans, crossing Bulgaria, Serbia, Hungary, and Slovenia and then Austria to connect with the main European pipeline network -- and bypassing crisis-hit Ukraine.
But amid a downturn in Russian relations with Brussels and Washington over the crisis in Ukraine, Moscow pulled the plug on the pipeline project in December.
Based on reporting by AP and AFP