Europe faces an increased gas squeeze starting Wednesday, when Russia's Gazprom said it would cut flows through the Nord Stream 1 pipeline to Germany to a fifth of its capacity.

With a dozen EU countries already facing reduced Russian supplies, Brussels is urging member states to prepare by saving gas and storing it for winter for fear Russia will completely cut off flows in retaliation for Western sanctions over its military operation in Ukraine.

Energy ministers approved a proposal for all EU countries to voluntarily cut gas use by 15% from August to March. The cuts could be made binding in a supply emergency, but agreements were made to exempt numerous countries and industries, after some governments had resisted the EU's original proposal to impose a binding 15% cut on every country.