Ukraine has agreed to pump enough gas into its storage facilities to maintain pressure in the system for Russian gas to reach Europe in winter, Russian Energy Minister Alexander Novak said on Wednesday.
Around 40 percent of Russian gas exports to the European Union traverses Ukraine.
Novak said that Ukraine had agreed to fill the storage facilities after talks in Brussels between officials from Russia, Ukraine and the European Commission on Tuesday.
A source close to the talks told Reuters that Moscow and Kiev had agreed an outline protocol on the gas trade and that ministers would meet later this month to try to resolve the key outstanding disagreements: on how long the protocol would last, the formula applied to discount prices for Ukraine and fees charged by Ukraine for the transit of gas over its territory.
Novak told reporters in Vienna: "They agreed on some positions of the protocol, including on pumping no less than 19 bcm into the storages before the forthcoming winter."
There was no immediate comment from Ukraine, which has said it needs from 14 to 19 billion cubic meters (bcm) in its storage to keep Russian gas transit to Europe intact. Ukrainian gas transport monopoly Ukrtransgaz has said it had 10.27 bcm of gas in its storage tanks as of June 1.