The Netherlands and Australia have formally accused Russia of being responsible for the 2014 downing of a Malaysia Airlines passenger jet in 2014 that killed 298 people.
The move came a day after international investigators concluded that the missile which smashed into the flight MH17 came from a Russian military brigade in Kursk.
At the time of the incident on July 17, 2014, pro-Russian separatists were fighting Ukrainian government forces in the region.
The Boeing 777 broke apart in midair, flinging wreckage over several kilometres of fields in rebel-held territory.
The two countries "hold Russia responsible for its part in the downing" of the Malaysia Airlines flight, the Dutch government said in a statement on Friday.
They may now move towards submitting the complex dossier to an international judge or organisation, it added.
"Australia and the Netherlands have now informed the Russian Federation that we hold it responsible under international law for its role in the bringing down of MH17," said Julie Bishop, Australia's Minister for Foreign Affairs.
"Australia and the Netherlands have requested Russia to enter into negotiations to open up a dialogue about its conduct and to seek reparations."
Al Jazeera's Rory Challands, reporting from Russia's second biggets city of St Petersburg, said the evidence provided by a Joint Investigation Team (JIT) led the Netherlands and Australia to believe that Russia was responsible.
"Holding a country legally responsible is a complex process but what Netherlands and Australia want is for Russia to enter into negotiations with both of them which will ultimately lead to reparations for the victims' families."
The Russian foreign ministry has denounced what it called an attempt to "discredit Russia in the eyes of the international community", but investigators, who painstaking recreated the BUK missile system's route from Kursk across the border into rebel-held eastern Ukraine using videos and photos, stood by their findings.
The team "has come to the conclusion that the BUK-TELAR that shot down MH17 came from 53rd Anti-aircraft Missile Brigade based in Kursk in Russia," top Dutch investigator Wilbert Paulissen said.
"The 53rd Brigade forms part of the Russian armed forces," he told reporters on Thursday.
Prosecutors have said that the BUK missile system was fired from the Ukraine village of Pervomaysk and later returned to Russian territory.
Investigation officials have not yet said who actually fired the missile, stressing that the probe continues.
But they have appealed for further information, especially from those who know people among the 53rd Brigade, as they seek to bring criminal charges against those who ordered the plane to be shot down.