Algeria and Libya may reduce deliveries to Europe in the next two to three years because of political instability, lack of investment and contract renegotiations, according to Carlo Malacarne, CEO of Italy’s Snam, Europe’s biggest gas transmission operator by pipeline length and storage capacity. Its Italian network includes entry points for gas arriving from North Africa and Russia.

International and U.S. upstream oil companies wrote down $38 billion in assets in the third quarter of 2015, the largest for any quarter since at least 2008 for this set of 46 companies. Low oil prices continue to have a significant effect on the value of companies' assets and future prospects as well as on current revenue.

"In 2016, geopolitical challenges will not go away. We have to keep pushing for diversification of energy sources," Sefcovic said, reiterating that the Commission would scrutinize whether the Nord Stream plan complied with EU rules.

Azerbaijan’s commercial gas production increased by 6.2 percent in 10 month of 2015, compared to the same period in last year, the State Statistical Committee of Azerbaijan reported on November 17.

“The fact is that the nation’s 21st century energy renaissance, which has made domestically produced natural gas cheap and abundant, has helped us achieve substantial and sustained emissions reductions without command and control style regulatory intervention,” said Gerard. “By contrast, the administration continues to hew to last century’s thinking that increased energy production and achieving climate goals are mutually exclusive, pursuing costly government mandates to detriment of the American consumer and our economy.

Credit crunch was expected to hit many independent U.S. oil producers, starving the industry of billions of dollars and further denting company budgets and drilling plans.

The U.K. government will make keeping the lights on the top priority with natural gas and nuclear power playing a central role in that goal, Energy and Climate Change Secretary Amber Rudd is expected to say in a major speech later Wednesday setting out a new energy policy for the country.

Gazprom would need to bring spot gas prices below $4 per million British thermal units (mmBtu), versus around $5.65 per mmBtu now, to shut Europe off to U.S. imports - a level Goldman Sachs expects could be reached by 2018/2019.

Gabriel explained that he would ensure that construction of the pipeline would remain legal in the eyes of the German authorities. Gabriel also made it clear that Brussels should have limited involvement with the project.

Tehran has recently strengthened ties with Moscow, which is considering providing two loans worth a total of $7 billion to Iran.