Ukraine's gas transport monopoly Ukrtransgaz says Russia has vowed to resume supplies of natural gas to Ukraine on December 11 after a six-month cut to deliveries due to a dispute over prices and unpaid debts.
The announcement was made on December 8 by Ukrtransgaz spokesman Maksim Belyavsky.
Ukraine transferred $378 million to Russia's Gazprom on December 5 in an advance payment for 1 billion cubic meters of Russian gas in December.
Ukraine's Energy Minister Volodymyr Demchyshyn had expected flows from Russia to resume on December 8.
Ukrtransgaz did not give a reason for the apparent delay.
Meanwhile, a Gazprom spokesman said the Russian state-controlled monopoly had received payment from Ukraine and was ready to restart gas shipments.
But spokesman Sergei Kupriyanov said the Ukrainian side had still not yet placed an order for gas at the close of business on December 8.
Kupriyanov said Ukraine continues to draw natural gas from its storage facilities underground and that could put the transit of gas at risk in case of prolonged cold spells.
Separately, Russia's energy minister, Aleksandr Novak, said on December 8 that Ukraine needs to buy at least 4 billion cubic meters of gas during the winter to ensure smooth transit of Russian gas to Europe.
Without Russian natural gas supplies, and with separatist violence in eastern Ukraine that has disrupted coal mining, Kyiv has been forced to implement widespread power cuts.
Ukrtransgaz said on December 8 that cold winter weather is draining Ukraine's natural gas reserves, which have fallen by more than 20 percent to 13.3 billion cubic meters since the heating season began in October.
Ukraine relies on Russia for about half of the natural gas it consumes and, despite storage, has a winter shortfall of around 3 billion to 4 billion cubic meters, depending on the weather.
Russia raised the price that it is charging Ukraine for natural gas after the ouster of the pro-Russian Ukrainian President Viktor Yanukovych's in February.
Russia cut off gas deliveries to Ukraine in June, but reached an agreement with Kyiv a month ago to restart deliveries on condition that Kyiv makes payments in advance for its gas deliveries and pays off some debt for previous shipments.
Ukraine's Energy Ministry on December 8 said it had granted the state energy firm Ukrinterenergo permission to import electricity from Russia to help address power shortages.
Turning to Russia for electricity supplies is a blow for Kyiv, whose relations with the Kremlin have been tense since Russia's annexation of Crimea in March and fighting in eastern Ukraine between government forces and Russian-backed separatists.
The state power firm Ukrenergo said on December 8 that it had imposed further restrictions on electricity consumption by heavy industry and by households in order to balance supply and demand.