Ukraine has filed a case against Russia at the United Nations' highest court, accusing Moscow of illegally annexing Crimea and illicitly funding separatist rebel groups in eastern Ukraine.
Kiev also is seeking compensation for deadly incidents including the 2014 shooting down of Malaysia Airlines Flight 17.
In the case announced Tuesday by the International Court of Justice, Ukraine accused Moscow of "intervening militarily in Ukraine, financing acts of terrorism, and violating the human rights of millions of Ukraine's citizens."
Kiev further alleged that Moscow's takeover of Crimea "brazenly defied the U.N. Charter, seizing a part of Ukraine's sovereign territory by military force." No date was immediately announced for hearings in the case, which is likely to take many months to complete.
Fighting between Ukrainian government troops and Russia-backed separatists has killed more than 9,600 people in eastern Ukraine since it began in 2014. Both Ukraine and the separatists are party to a truce under which both should cease fire and stop advancing.
Russia has been in control of Crimea since it annexed the Crimean peninsula in March 2014 after a hastily called referendum.
From the time the armed conflict in eastern Ukraine began in April 2014, the Ukrainian government referred to Russian interference as terrorism.
Ukraine has accused Russia of financing separatist rebels in the eastern Donetsk and Luhansk regions as well as sending Russian troops there. The Kremlin has denied the accusations although President Vladimir Putin said in October Russia "had to defend Ukraine's Russian-speaking population."
Officially, Russia has only sent humanitarian aid to eastern Ukraine. Multiple media have reported how Russian humanitarian aid has been mismanaged and often sent directly to rebel troops, not the civilian population.
About six months into the conflict, rebel authorities in Donetsk and Luhansk in 2014 began paying out pensions and benefits to retirees and families. Rebel officials insisted that the funds come from the taxes they collect, but commanders privately admitted that the money comes directly from Russia. The Kremlin has denied that.
The filing also asked the court to rule that Russia is legally responsible for crimes including the downing of Flight MH17.
An international criminal probe concluded last year that a missile that destroyed the Malaysian passenger jet over Ukraine in 2014 and killed all 298 people aboard was fired from rebel-controlled territory by a mobile launcher trucked in from Russia and hastily returned there.
Moscow denounced the findings of the Dutch-led inquiry as "biased and politically motivated."
Ukraine also asked the Hague-based world court to order interim measures while the case is going on, including ordering Moscow to halt the transfer of funds and arms to separatist rebels in Ukraine and to stop its persecution of ethnic Tartars in Crimea.
Rulings by the court are final and legally binding.