Ukrainian Prime Minister Yuriy Yekhanurov said that Kyiv is drafting documents for possible appraisal by the Stockholm Chamber of Commerce, whose Arbitration Institute is internationally recognized as a neutral venue in which to settle commercial disputes.
However, Russia must also agree to arbitration if the case to be taken up .
Earlier on 23 December, Russia's gas giant Gazprom repeated its threat to halt gas deliveries to Ukraine on 1 January unless Ukraine agrees to new prices.
Ukraine currently pays $50 per 1,000 cubic meters of Russian gas. Moscow wants to raise that price by around 400 percent, to reflect world market prices.
RFE/RL Belarus, Ukraine, And Moldova Report
SUBSCRIBE For weekly news and analysis on Belarus, Ukraine, and Moldova by e-mail, subscribe to "RFE/RL Belarus, Ukraine, And Moldova Report."