With temperatures in some regions as low as minus 35 degrees Celsius, "I can confirm that there has been a decrease in gas deliveries in various member states -- Poland, Slovakia, Austria, Hungary, Bulgaria, Romania, Greece and Italy," EU spokeswoman Marlene Holzner said.
The British Broadcasting Corp. reported Saturday freezing temperatures have led to the deaths of 100 people in Ukraine, "most of them homeless."
Russian Prime Minister Vladimir Putin said in a meeting with state-owned energy concern Gazprom's Deputy Chairman Alexander Medvedev, "I am asking you to make a real effort to supply the demands of our foreign partners, given that the top priority of our energy companies, including Gazprom, is to supply Russian customers."
Europe receives a quarter of its natural gas supplies from Russia. With supplies tight this year, Putin said there was justification for South Stream and Nord Stream pipelines, RIA Novosti reported.
"Today, we should recall those who were preventing us from building the Nord Stream pipeline. But for them, the second leg [of the pipeline] would have already been put into operation," Putin said.