MOSCOW, May 28 (Xinhua) -- President Vladimir Putin said Wednesday Russia had been kind to Ukraine on gas supplies, and instructed the government to work out a cooperation scheme if Kiev paid some debts.
"All objective observers understand that Russia's position regarding its energy cooperation with Ukraine is not merely that of a partner, it is that of a friend," Putin told a government meeting.
He said Russia had supplied Ukraine with natural gas for free in volumes exceeding the yearly supply to Poland.
"That can't go on forever, it's impossible," Putin said, adding it was senseless to question the gas contract Moscow and Kiev signed in 2009.
In 2009, Russian gas giant Gazprom and its Ukrainian client, Naftogaz, signed an agreement to end a pricing dispute which jeopardized transit flows to Europe. Under the terms of the contract, Ukraine agreed on take-or-pay clauses, where customers must pay for gas whether they use it or not.
"The moment is approaching when a tough measure envisaged by the contract could be implemented," the Interfax news agency quoted Putin as saying.
Still, he said, Moscow hoped such a development could be avoided if Ukraine began payments as it recently agreed.
Putin instructed Prime Minister Dmitry Medvedev to study the possibilities of future energy cooperation with Ukraine if the latter repaid its debts.
On Tuesday, Gazprom head Alexei Miller said Kiev had agreed to consider paying off part of its multi-billion debt.
"The Ukrainian side agreed to consider payment of 2 billion U.S. dollars by Friday," Miller told the Russia-24 TV channel, adding Kiev must also pay 500 million dollars for ongoing May supplies.
In addition, Naftogaz must prepay to the Russian supplier 1.659 billion dollars before June 2.
Gazprom estimates the total debt of Naftogaz will exceed 5.2 billion dollars by June 7.