The Obama administration set a course for a more aggressive campaign to quell the Russian-backed insurgency in eastern Ukraine, blaming Moscow for the crash of Malaysia Airlines Flight 17 and saying it was likely downed by a ground-to-air missile from rebel territory.

The plane carrying 283 passengers and 15 crew crashed in the battle-torn eastern Ukraine region of Donetsk, where pro-Russia separatists are occupying several towns in a three-month conflict.

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