White House adviser Tony Blinken says there is evidence that Russia is preparing to deliver more powerful rocket launchers to separatist rebels in eastern Ukraine.
Western powers have accused pro-Russian rebels in the area of shooting down Malaysia Airlines flight MH17 with a rocket.
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More than 400 people have died in a week of bombardment in rebel-held eastern Ghouta in Syria.
Coldest air yet to arrive
The band's hit singles include You To Me Are Everything, Can You Feel The Force?, and Can't Get By Without You.