Giuseppe Spatafora told The Associated Press that the reduction of US troops on NATO's eastern flank could undermine NATO's deterrent effect.

"Russia could be tempted to test NATO even further, without seeking to open a new front, but checking how the alliance responds" in the future to more drone incidents or acts of sabotage.

Giuseppe said that while the full extent of the American withdrawal is not yet known, "we do know the direction of travel: fewer US troops and assets, and an expectation that Europeans will fill the gap."