Gazprom pointed out that, according to the relevant arrangements with Ukraine, Naftogaz is obliged to annually pay for minimal annual quantity of Russian gas.
"Proceeding from the contract terms, the minimal annual quantity of gas in the third quarter of 2015 amounted to 10,485 billion cubic meters. Taking this into account, as well as the volume of gas delivered by Gazprom to Ukraine in the third quarter of 2015, an invoice for $2,549 billion has been raised against Naftogaz," the statement reads.
In September 2015, Gazprom confirmed that the "take or pay" rule, obliging Ukraine to pay for the volume of gas specified in the contract, regardless of the real volume of purchases, would be canceled for the fourth quarter of 2015 and the first quarter of 2016.
The Russian company has demanded the Ukrainian side pay the bill within ten days.
"Ukraine effectively refused to purchase Russian gas in the third quarter of 2015, as such, there were no agreements on the cancellation of the 'take or pay' rule during that period of time," Gazprom CEO Alexey Miller said, as quoted in the statement.
In October 2015, Ukraine's energy company Naftogaz said that the country was completing the purchase of gas from Russian energy giant Gazprom, and a decision to continue to import gas from this supplier would depend on price. The following month, Ukraine halted purchases of Russian gas, saying the pricing offered by its European partners was much lower than that offered by Moscow.