The Russian planes included TU-95 bombers, IL-78 tankers and SU-35 fighter jets, NORAD said in a written statement.

NORAD described the interception as "routine" and said they happen roughly six or seven times per year in the so-called Alaska Air Defense Identification Zone.

"This Russian activity in the North American ADIZ occurs regularly and is not seen as a threat," NORAD aid in the statement. "NORAD tracks and positively identifies all military aircraft that enter the ADIZ, routinely monitors aircraft movements and as necessary escorts them from the ADIZ."

The U.S. aircraft involved in the incident included F-16 and F-22 fighter jets, KC-135 stratotankers and E-3 AWACS, according to the statement.

(Reporting by Dan Whitcomb; Editing by Cynthia Osterman)