Ukraine is preparing to take Russia to court to prove it has violated accords in an increasingly combustible gas dispute that has ended a thaw in relations, President Viktor Yanukovych said Tuesday. Ditching diplomatic language, Yanukovych reminded Moscow that Ukraine was an independent state, not a "poor relation", and accused his counterpart Dmitry Medvedev of using "absolutely incorrect" rhetoric. "Russia's position is categorically unacceptable and if it does not change then we will go to international arbitration," Yanukovych told the Kommersant daily in an interview. "We have already drawn up the materials for going to court. We are absolutely sure that international agreements have been violated," he said. "Court, yes, it's an extreme measure but nothing has changed for one-and-a-half years." Ukraine is seeking a revision to accords with Russia signed by the previous Ukrainian government to obtain lower prices for its gas imports from Russia's Gazprom. Yanukovych said that Kiev is overpaying by $5-6 billion annually. Yanukovych said the basis of Ukraine-Russia gas relations should be the 2001 accords -- not the 2009 10-year deal that ended a cut in supplies signed by ex-prime minister Yulia Tymoshenko, now on trial for abuse of power. "The price is not fair for Ukraine. The conditions have been set out as if for an enemy," he said. He said Ukraine was paying way more for Russian gas than Germany. If Kiev continued "overpaying" in the next 10 years, then Ukraine would lose $60 billion, or 20 percent of the budget anually. Recent tough rhetoric against Kiev by Medvedev was "completely incorrect", Yanukovych added. "We are not poor relations. We are an independent state." Yanukovych was seen as a pro-Kremlin figure when he came to power after defeating the leaders of the 2004 Orange Revolution in 2010 polls. But he has since set integration with the European Union as the goal of his presidency. However there are also growing tensions with the European Union and the United States, which have expressed alarm over the trial and detention of Tymoshenko.