Austrian oil company OMV is one of Russian gas giant Gazprom's partners in the pipeline project connecting Russia to Germany, which has been completed but is not yet operational as it is awaiting German and EU regulatory approval.

Indirect talks between Iran and the United States on salvaging the deal with world powers resumed on Tuesday after a 10-day break,

“When it comes to the Vienna talks on the lifting of sanctions, one of the key issues is to get the necessary guarantees, especially from the Western parties, about the fulfilment of their commitments,”

European Commission Vice President Josep Borrell said Russia was using Europe's reliance on its energy exports for "geopolitical gain in the middle of a surge of energy prices worldwide."

She did acknowledge, however, that Gazprom was fulfilling its contracts, "but only at the bottom end of its commitments."

Already, oil prices have hit seven-year highs in recent days over the ratcheting tensions between the West and Russia over Ukraine.

Oil, gas and resources companies, and trading desks, are fretting about the provisions around sanctions on Russian extractive industries, financial institutions and banks, Russian leaders and businessmen, and the use of global services, such as wire transfers.

Efforts to impose sanctions on the Nord Stream 2, an undersea gas pipeline from Russia to Germany that would give Moscow enormous leverage over Europe, have long drawn bipartisan support on Capitol Hill,

Iran insists on immediate removal of all Trump-era sanctions in a verifiable process.

The U.S. and some European opponents of Nord Stream 2 say it will make Europe too reliant on Russian gas, allowing Moscow to expand its political, economic and military influence. But other governments say it is vital to secure energy supplies, as gas prices surge and the threat of power outages looms.