A set of US nuclear-bomber planes were joined by NATO allies – Italy, Spain and Romania – in a mission over Europe on Wednesday in a stark warning to Russian President Vladimir Putin as tensions rise.

Striking footage shows one of the American B-52 planes soaring above the clouds alongside fighter jets from Spain, Italy and Romania.

The NATO air command tweeted: “The B-52s are training with Allied Air Forces during their BTF mission strengthening our Euro-Atlantic partnership.”

Details about the mission have been revealed amid the ongoing tension between NATO allies and Russia, as the Ukraine war rages on.