WASHINGTON: US President Barack Obama said Friday that a surface-to-air missile fired from separatist-held territory in eastern Ukraine was to blame for the “unspeakable” downing of a Malaysian airliner carrying nearly 300 people.

Obama said the disaster was a “wake-up” call for European nations that have been wary of toughening sanctions against Russia over its role in Ukraine and revealed that one American was among the dead in the disaster.

He also demanded that Russian President Vladimir Putin act to control pro-Moscow rebels in Ukraine, and said they would not have been able to hit an airliner flying at 30,000 feet without Russian equipment and training.

In his most extensive comments on Thursday’s tragedy to date, Obama mourned the men, women, children and infants who died when the plane was brought down en route from Amsterdam to Kuala Lumpur.

“Their deaths are an outrage of unspeakable proportions,” Obama said, bemoaning the fact that those killed had nothing to do with the battle in Ukraine between the Western-backed government in Kiev and pro-Moscow rebels.

“Evidence indicates that the plane was shot down by a surface-to-air missile that was launched from an area that is controlled by Russian-backed separatists inside of Ukraine,” Obama said.

Earlier, a US intelligence official told AFP that there were indications from satellite and other data that separatists shot down the Boeing-777, but said no final conclusion had been drawn.

Obama called for an immediate cease-fire that he said separatist forces must honor and warned evidence at the crash site must not be tampered with.

“No one can deny the truth that is revealed in the awful images that we all have seen, and the eyes of the world are on eastern Ukraine, and we are going to make sure that the truth is out,” said the president, speaking in the White House briefing room.

Obama blamed Russia and President Vladimir Putin for creating the instability that led to the jet being shot down.

“We want Russia to take the path that would result in peace in Ukraine, but so far, at least, Russia has failed to take that path,” he said. The president said that one American was now known to have died on the plane, naming him as Quinn Lucas Schansman, a dual Dutch-US citizen.