Ten European governments -- the easternmost members of the European Union -- have complained in a letter that Russia's plans to extend its natural-gas link to Germany run counter to EU interests and risk further destabilizing Ukraine.
The letter, written on November 26, was signed by Poland, Bulgaria, the Czech Republic, Slovakia, Hungary, Romania, Greece, Estonia, Latvia, and Lithuania.
It calls for a summit-level EU debate on the Nord Stream II project.
Reuters quoted the letter as saying: "The position of the European Commission on the Nord Stream II project will also essentially influence the perception of the EU's common foreign and security policy among its core allies and traditional partners."
A group of European companies in September signed an agreement with Russia's state-controlled Gazprom to expand its Nord Stream pipeline to Germany, bypassing Ukraine.
On November 25, Gazprom said it would halt gas deliveries to Ukraine.
Kyiv has said it could find cheaper supplies elsewhere.
Based on reporting by Reuters, Platts, and Naturalgaseurope.com