As Russia and Ukraine brace for a winter gas war, Naftogaz needs $1 billion to fill reservoirs to the needed level this summer. Russia’s Gazprom has filled European reservoirs with 60% more gas than normal for this season, Andriy Kobolyev, the Naftogaz CEO, warns in a Facebook post. Russia’s push to stockpile in the EU is also evidenced by a 8% y-o-y rise in Russian gas volumes crossing Ukraine since January. In May, this gas transit was up 16.4%, Ukrtransgaz reports Thursday. Russia threatens to abandon its 10-year transit contract with Ukraine when it expires Jan. 1.