WASHINGTON - The United States said Thursday that Russia's support for separatists in Ukraine created the conditions in which a Malaysian airliner was apparently shot down with the loss of nearly 300 people.
Washington also demanded an "unimpeded" international inquiry into the disaster and warned evidence among scattered debris, on an escalating civil war battlefield in Ukraine, should not be tampered with.
The White House response to the tragedy was a clear rebuttal to Russian President Vladimir Putin's charge that Ukraine's crackdown on separatist rebels stoked tensions that led to the crash.
"While we do not yet have all the facts, we do know that this incident occurred in the context of a crisis in Ukraine that is fueled by Russian support for the separatists, including through arms, materiel, and training," the White House said in a statement.
In calls with pro-Western Ukrainian President Petro Poroshenko and Dutch Prime Minister Mark Rutte, President Barack Obama put down an early marker on the necessary conditions for an air accident investigation that will have to take place in the middle of an escalating civil war.
More than 150 Dutch citizens are believed to be among the dead when the Malaysia Airlines jet crashed. US officials said the jet was hit by a surface-to-air missile but could not say who launched the attack and from where.
The White House said that Obama told Rutte the United States was prepared to contribute "immediate assistance" for "a prompt, full, credible and unimpeded international investigation."
Obama and Rutte also agreed on the need for "immediate access" to the site of the crash in territory held by pro-Russia separatists, the statement said.