Trade with the United States could remove obstacles inhibiting European efforts to break Russia's grip on the energy sector, a commissioner said Thursday.

European Trade Commissioner Cecilia Malmstrom told policymakers in Brussels the next phase of negotiations on the Transatlantic Trade and Investment Partnership would focus on rules on energy.

"Those rules can help Europe address the challenge presented by our dependence on Russian energy, by removing the legal obstacles to U.S. exports to the European Union," she said in her remarks. "This dependence has limited Europe's freedom of maneuver in the face of Russia's unacceptable actions in Ukraine."

European markets get about a quarter of their natural gas needs met by Russia, though most of that runs through Soviet-era transit networks in Ukraine. Lingering contractual disputes between Kiev and Russian gas supplier Gazprom, as well as the geopolitical fallout from crises in eastern Ukraine, adds risks to conventional gas delivery options.

European planners are working to diversify the energy sector by courting rival suppliers in the Caspian region. An increase in natural gas production from the United States has led to calls for exports to Europe. That's unlikely without a free-trade agreement, however.

In a 2014 report, the European commission said the number of export restrictions is problematic in an economy where connections are strong, particularly in the trade of natural resources.

"The tendency to restrict participation of foreign companies in public tenders remains strong, in particular in the United States," the report said.

Speaking in January, U.S. Assistant Secretary of State of European Affairs Victoria Nuland said both sides of the Atlantic would benefit from improved trade relations.

"In the area of energy security, we're not just talking the talk; now we're walking the walk," she added.

Early last year, members of an EU civil liberties committee said the trade deal with the United States was in serious risk because of spying allegations leaked to the media by Edward Snowden, a former contractor for the National Security Agency.