President Barack Obama piled pressure on Russian President Vladimir Putin on Monday to force pro-Russian separatists to stop blocking an international investigation into the shoot-down of a passenger jet last week.
In remarks at the White House, Obama said Russian-backed separatists in eastern Ukraine have kept investigators away from the site of the downed Malaysian Airlines plane, at times firing their weapons into the air.
"What are they trying to hide?" he said.
Obama said Putin and Russia have a direct responsibility to compel separatists to cooperate with the investigation and that the burden is now on Moscow to insist that separatists stop tampering with the investigation.
Obama called for international investigators to have "immediate and full access" to the site in eastern Ukraine.
Obama accused pro-Russian separatists in the area of removing evidence and bodies from the crash site.
The president says the burden is on Russia and Putin to compel the separatists to cooperate with the investigation. Obama says that if Russia continues to violate Ukraine's sovereignty, Moscow "will only further isolate itself" and the economic costs will continue to increase.
The White House says the missile that brought down the Malaysia Airlines plane was fired from an area controlled by the separatists.
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