President Dmitry Medvedev ordered Gazprom to recover a $2.4 billion debt owed by Ukraine for natural gas deliveries, days after the gas producer hailed progress on a new supply accord.

"This is a lot of money for any state and for any company, including Gazprom," Medvedev told Gazprom CEO Alexei Miller on Thursday, Vesti-24 reported.

Gazprom may raise the price it charges Ukraine for gas to more than $400 per 1,000 cubic meters from Jan. 1, Miller told Medvedev, according to e-mailed comments from Gazprom.

All the necessary documents for a long-term contract are ready on the corporate side, Miller said.

Ukraine should either pay the debt voluntarily or be forced to clear it, Medvedev said.

State energy firm Naftogaz Ukrainy said, however, that its debt to RosUkrEnergo, a Russian-Ukraine intermediary gas trader co-owned by Gazprom, does not exceed $1.3 billion.

"Today, our debt, with all of the nuances taken into account, is $1.26 to $1.27 billion. … We are buying all the gas from RosUkrEnergo, so we do not have any debts to Gazprom," Vladimir Trikolich, Naftogaz's deputy head, told reporters.

Ukraine imports about 55 billion cubic meters of gas annually, buying most of it from RosUkrEnergo.

Bloomberg, Reuters