The Pentagon said Saturday that two Russian fighter jets warded off a US B-52 bomber in international airspace above the Black Sea.
The incident occurred early Friday, the US European Command said in a statement.
The Russian S-27 jets conducted an "unsafe and unprofessional" intercept as the pilots flew 100 feet (30 meters) from the bomber.
Six US B-52 Stratofortress strategic bombers flew above countries as part of support for NATO alliance members. .