Russia has ordered Ukraine to make pre-payments for gas supplies for all future deliveries due to Ukraine's unpaid bills that now total several billion dollars.
Energy Minister Aleksandr Novak said in a May 8 statement, "Russia is introducing a pre-payment regime for gas deliveries to Ukraine," starting June 1 after Ukraine missed a May 7 deadline to pay off its $3.5 billion gas debt.
Ukraine pledges to pay off the debt but Kyiv objects to the new price state-owned gas company Gazprom is charging Ukraine for gas supplies.
In March, after former Ukrainian President Viktor Yanukovych was ousted, Gazprom raised the price it charges Ukraine for gas from $285 per 1,000 cubic meters to $485.
Ukraine Energy Minister Yuri Prodan said on May 8 Kyiv was willing to pay a fair market price for gas.
But Prodan said Kyiv "will not be able to pay for gas deliveries" at the new price set by Gazprom, which he described as "unjustified," and "discriminatory."
The announcement of pre-payment rules for Ukraine came the same day Lithuanian officials announced Gazprom would cut the price it charges Lithuania for gas by more than 20 percent.
Based on reporting by AFP, Interfax and Itar-Tass