Russia's Gazprom assured European customers it would continue to supply their gas, after its threat to halt supplies to transit nation Ukraine next month over non-payment.
Any shortfall would be the fault of Ukraine, chief executive Alexei Miller told Russian television. Moscow blamed theft by Ukraine for a disruption to exports in a previous dispute.
Russia has warned that it will not supply Ukraine with gas in June unless Kiev pays in advance $1.66 billion by June 2, raising fears that gas piped to Europe through Ukraine could be affected.
"Gazprom will simply supply Ukraine as much as gas as it will have bought, and to the Russian border with Ukraine we will send as much gas as Europe should get and Ukraine should transit," Miller said in an interview on Rossiya-24 television.
"It would be our Ukrainian partners' responsibility for a so-called unauthorised off-take. But Gazprom from its part will do everything to ensure that European customers have no problems," Miller told the news show Vesti.
Gazprom said on Friday that exports to Europe via Ukraine remained stable, as they have so far during mounting tensions between Moscow and Kiev - and Russia and the West - since the removal of a Moscow-friendly Ukrainian president in February.
Previous disputes over gas have left Europe, which gets around a third of its gas needs from Russia, with limited supplies at the height of winter.
Ukraine, which owes Russia $3.5 billion for past gas deliveries, wants to change the conditions of a 2009 contract that locked Kiev into buying a set volume, whether it needs it or not, at $485 per 1,000 cubic meters.
On Friday, Russian Energy Minister Alexander Novak said Russia was ready to discuss a discount if Kiev pays off more than the $2.2 billion it owed as of April 1 in a sign the two sides were edging toward a potential compromise.