Throughout February, U.S. military units will spread out across Poland, the Baltic states, Bulgaria, Romania and Germany for training, exercises and maintenance as part of a NATO buildup that has angered Russia.
Hundreds of U.S. tanks, trucks and other military equipment arrived by ship in Germany in early January, bound for eastern Europe.
Around 4,000 U.S. troops are being deployed for exercises in NATO states near Russia, part of a series of measures aimed at reassuring them after Russia's 2014 annexation of Crimea.
In addition to U.S. troops stationed in Poland, NATO members Germany, Canada and Britain are also sending battalions of up to 1,000 troops each to the former Soviet republics of Estonia, Latvia and Lithuania. The Baltic Deterrent Force, which was agreed at the Warsaw summit in Oct 2016, is expected to be in place near Russia's borders by May.
Exercises in Poland and the Baltic republics are scheduled to take place from Feb 27-Mar 4.
NATO says the planned deployments are purely defensive, but Russia has rebuked what it sees as western aggression.
Date written/update: 2017-01-13