Ukraine's state energy company, Naftogaz, confirmed on Tuesday that it had repaid $1.45 billion (1.15 billion) of its outstanding natural gas bill to Russian company Gazprom.
It must now pay $1.65 billion before the end of the year, as part of an EU-brokered deal reached last week.
According to the agreement, Brussels is helping Kyiv finance deliveries in advance as requested by Gazprom.
The Russian energy company had halted natural gas deliveries to the eastern European country in June after its newly elected government failed to pay off previous debts.
The two parties had also argued over the price. Gazprom had wanted $485 per 1,000 cubic meters. Kyiv complained that the price was too high, noting that it was double that of the original offer to Kremlin-backed President Viktor Yanukovych before he was forced to step down earlier this year.
Under the accord reached last week, Ukraine will pay $378 per 1,000 cubic meters of gas through the end of 2014 and then $365 through the end of March.
The last-minute deal was seen as a victory for mediating EU Energy Commissioner Günther Oettinger, who was to leave office Friday, making way for a new European Commission and his Slovak successor, Maros Sefcovic.