The State Department says the U.S. is deeply concerned that the separatists in eastern Ukraine have refused to allow monitors safe and unfettered access to the site where a Malaysian airliner was shot down with nearly 300 people aboard.
Spokeswoman Jen Psaki says the site was not secured and notes multiple reports of bodies being removed, debris taken away, and potential evidence tampered with.
She calls the situation "unacceptable and an affront to all those who lost loved ones and to the dignity the victims deserve."
Meanwhile, the latest U.S. intelligence assessment suggests that more than one missile system was provided to the separatists by the Russians in the last week or so.
A U.S. official tells The Associated Press that while there is not 100 percent certainty, there's a growing belief that the systems were provided by the Russians.