The North American Aerospace Defense Command said it scrambled one E-3 Sentry command-and-control aircraft, two F-16 fighter jets and two KC-135 refuelling tankers on Sunday to identify a Russian Il-20 reconnaissance plane operating inside the Alaskan Air Defense Identification Zone. The Russian aircraft remained in international airspace and did not enter the sovereign airspace of either the United States or Canada. It was the third interception in less than a week, following similar encounters on 20 and 21 August. NORAD described such activity as routine and not a direct threat, noting that aircraft entering the ADIZ are required to identify themselves for security reasons. The command said it employs a layered defence network of satellites, radars and fighter aircraft and "remains ready to employ a number of response options in defence of North America."