Soldiers set up temporary camps in the forest and patrolled in the airfield, while others worked on utility and air defense vehicles stationed on the site near the city of Przemysl.

The site is one of several new operating bases in eastern Poland, where recent troop deployments are intended to reassure NATO allies and deter Russian aggression, U.S. army officials said.

The U.S. committed to deploying some 4,700 new troops to Poland alone since tensions rose, at the start of the year, over Russia's military build-up at Ukraine's borders and fears of a potential invasion.