"The first batch has arrived at the airport in Jesionka" in southwestern Poland, Major Przemyslaw Lipczynski said, adding that the bulk of a contingent of 1,700 US soldiers would come "soon".

He said the soldiers who arrived Saturday were from the 82nd Division.

Washington said last week it would send about 3,000 additional troops to eastern Europe to defend NATO members against any "aggression".

Washington is sending 2,000 troops stationed in the US. They are being flown to Germany and Poland. Another 1,000 already in Germany are being sent to Romania.

Western capitals have accused Russia of amassing some 100,000 troops on the borders of pro-Western Ukraine in preparation for an invasion and have vowed to impose devastating sanctions on Moscow if it attacks.