MOSCOW, June 16. /ITAR-TASS/. For the period that Ukraine has not paid for Russian gas supplies, it has pumped astronomical volumes into its underground gas storage facilities, Gazprom’s CEO Alexey Miller said Monday.

Out of 12.5 billion cubic meters of gas in Ukraine’s underground storages, 11.5 billion cubic meters is Russian gas that Ukraine has not paid for, Miller added.

He said the storage facilities should have over 18 billion cubic meters to be prepared for winter.