Four Russian warplanes on Tuesday flew just outside of United States airspace near Alaska, the North American Aerospace Defense Command said, marking the latest incident involving Russian aircraft off the coast of the U.S. state.
The military operation was routine, according to the agency, which detected and tracked the planes. Although the Russian aircraft remained in international air space, they entered a region beyond U.S. and Canadian sovereign air space called the Air Defense Identification Zone (ADIZ), where aircraft are expected to identify themselves, according to NORAD.
The ADIZ is a stretch of international air space bordering the sovereign space around the U.S. and Canada, which both countries monitor in order to, ideally, readily detect all aircraft passing through. Surveillance in the defense zone is maintained for national security reasons.
NORAD said it uses a “network of satellites, ground-based and airborne radars and fighter aircraft to detect and track aircraft and inform appropriate actions” and “remains ready to employ a number of response options in defense of North America.”