WASHINGTON - US President Barack Obama says Russian Vladimir Putin has "direct responsibility" to compel Ukrainian separatist to cooperate with international investigators, sharpening his previous statements to make clearer that the US considers Russia complicit in the shooting down of Malaysia Airlines Flight 17.
While Mr Obama had earlier stopped short of pointing the finger directly at the Russians, he issued a harsh condemnation of Moscow's activities in Ukraine at the White House on Monday.
"Russia has extraordinary influence over these separatists, nobody denies that. Russia has urged them on; Russia has trained them; we know that Russia has armed them with military equipment and weapons, including anti-aircraft weapons; key separatists leaders are Russian citizens. So given their influence over separatists, Russia and Putin in particular has direct responsibility to compel them to cooperate with the investigation. That is the least that they can do," he said.
US intelligence have declared in recent days that they have evidence that the missile that shot down the plane was fired form territory in Ukraine controlled by Russian separatists. They have also said that they believe the surface-to-air missiles used was moved across the border from Russia to Ukraine.
Secretary of State John Kerry had also made the case that Russia was responsible from the tragedy. He told Sunday morning news shows: "There's enormous amount of evidence... that points to the involvement of Russia in providing these systems, training the people on them. We know that the separatists have shot down 12 aircraft in the last couple of months, among them two transport planes."
Mr Obama"s remarks came shortly after a similar speech by British Prime Minister David Cameron. Mr Cameron said that he told Mr Putin in a phone call that there should be no more "bluster or obfuscation" and urged the Russian leader to act to calm the conflict and aid the repatriation of the dead.
On Monday, the US president also warned Russia of increasing isolation and costs if they resist a diplomatic resolution to the Ukrainian crisis, although he did not specify what sort of actions the US will be prepared to undertake.
"My preference continues to be finding a diplomatic resolution within Ukraine, I believe that can still happen. That is my preference today and that will continue to be my preference. But if Russia continues to violate Ukraine's sovereignty and to back these separatists and these separatists become more and more dangerous and now become a risk not only to the people inside Ukraine but the broader international community, then Russia will only further isolate itself from the broader international community and the costs for Russia's behavior will only continue to increase," he said.