The take-or-pay principle will return to relations between Russia's Gazprom and Ukraine's national oil and gas company Naftogaz Ukrainy starting April 1, Energy Minister Alexander Novak told reporters after a meeting with the vice president of the European Commission for energy, Maros Sefcovic.

"The terms of a contract that envisions the take-or-pay [principle] go into effect on April 1. This is the point that Ukraine is disputing in Stockholm. It will continue to be in effect," Novak said.

He declined to give further comment on the meeting with Sefcovic, noting only that he would prefer to comment after trilateral talks are held with Ukraine.