Russia's top natural gas producer Gazprom said on Thursday Ukraine has to increase the level of gas in storage to ensure its stable transit to Europe. Gazprom also said Ukraine's unpaid gas bill for Russian gas stood at $2.2 billion, up from the previous estimate of $1.7 billion.
Voice of Russia: Gazprom urges Ukraine to fill gas storage for stable flows to Europe
Russia's top natural gas producer Gazprom