By Phil Stewart, Vladimir Soldatkin and Alexander Marrow WASHINGTON/MOSCOW (Reuters) – A Russian troop buildup along its border with Ukraine includes supplies of blood for the wounded, three U.S. officials told Reuters, a detail reinforcing U.S. comments that Russia “clearly” now has the capability to move on its neighbour. The disclosure by the officials, speaking on condition of anonymity, adds to growing U.S. concern that Russia could be preparing for a new invasion of Ukraine as it has amassed more than 100,000 troops near its borders. The Russian Defence Ministry did not immediately respo…