National joint-stock company Naftogaz Ukrainy in April could start recovery of $2.6 billion debt from Russia's Gazprom to execute the award of the Arbitration Institute of the Stockholm Chamber of Commerce, Naftogaz Chief Commercial Officer Yuriy Vitrenko has said.

"[The appeal to courts] could start in the near future, in April. We have warned them," he said on the 24 Channel TV late on Wednesday.

He said that the recovery could take up to six months, while Naftogaz hopes that the Russian company would execute the arbitration tribunal's award in the near term in an honest manner. He said that Gazprom has not yet filed a counterclaim against the tribunal's award on the gas transit contract.

"From a point of view of law, even if they already filed the counterclaim, it does not stop the execution of the arbitration tribunal's award. That is they must pay this money to us, and then wait for a year and a half until their counterclaim is heard and the respective decision is made," he said.

Vitrenko did not rule out the possibility of arresting the Russian company's gas in underground storage facilities in Europe or shares of the Nord Stream pipeline operator in a Swiss court for debt recovery.