U.S. air defense troops are training rapid deployment of Patriot missile launchers in Poland amid concerns that the conflict between Russia-backed rebels and government forces in Ukraine is threatening the security in the region.

Some 100 U.S. troops and 30 vehicles from the 7th Air Defense Regiment are practicing with Poland's troops at a test range in Sochaczew, near Warsaw. The exercise is aimed at showing the U.S. Army's capacity to deploy Patriot systems rapidly within NATO territory.

Speaking in fluent Polish, U.S. Ambassador Stephen Mull said Saturday that the U.S. is always ready to support Poland in times of need.

Meanwhile in Szczecin, on the Baltic coast, the NATO Multinational Corps Northeast held a ceremony to mark the procedure of raising its status from low to high reaction readiness.