WASHINGTON

The North American Aerospace Defense Command, or NORAD, tracked a Russian military aircraft operating in the Alaskan Air Defense Identification Zone (ADIZ) on Monday.

"The Russian aircraft remained in international airspace and did not enter American or Canadian sovereign airspace," NORAD said in a statement, adding the Russian activity in ADIZ occurs "regularly and is not seen as a threat."

"NORAD remains ready to employ a number of response options in defense of North America," it added.​​​​​​​

An ADIZ begins where sovereign airspace ends and is a defined stretch of international airspace that requires the ready identification of all aircraft in the interest of national security, according to the statement.

NORAD said it employs a layered defense network of satellites, ground-based and airborne radars and fighter aircraft to detect and track aircraft and inform appropriate actions.