Ukrainian President Petro Poroshenko says Russia "must be held accountable" for downing Malaysian Airlines Flight 17 in 2014 over the war zone in eastern Ukraine.
Poroshenko wrote on Facebook on July 17, the fourth anniversary of the tragedy, that Ukraine "has been providing investigators with all necessary assistance."
MH17 was shot down over the conflict zone in Ukraine's Donetsk region on July 17, 2014, killing all 298 people on board.
"A joint investigative group consisting of representatives of Australia, Belgium, Malaysia, Netherlands, and Ukraine has established that the aircraft was shot down by a Buk missile complex that belonged to Russia's armed forces and brought [to the territory controlled by Russia-backed separatists] from the Russian Federation. Therefore, Russia must be held accountable for that terrorist act," Poroshenko wrote.
MH17 TIMELINE: A history of the disaster (click to view)
Earlier in May, the Dutch-led Joint Investigative Team said in a statement that the international criminal investigation had concluded that the Buk missile that shot down the plane came from Russia's 53rd Antiaircraft Missile Brigade.
Russia denies any responsibility.
In late June, European Union leaders called on Moscow to "accept its responsibility and fully cooperate with all efforts to establish truth, justice, and accountability" in response to the incident, and extended the bloc’s economic sanctions penalizing Russia for its aggression in Ukraine.
The sanctions, which mainly hit Russia's banking and energy sectors, were first imposed in the summer of 2014 after Russia illegally annexed Ukraine's Crimean Peninsula and began fueling the conflict in eastern Ukraine by backing separatists fighting government forces there.
More than 10,300 people have been killed in the conflict, and EU leaders have said the sanctions won't be lifted unless Russia and other parties to the conflict make progress toward carrying out agreements aimed at solving the conflict.