US detects Russian aircraft flying in Alaska Air Defense Identification Zone

The North American Aerospace Defense Command (NORAD) has detected and tracked four Russian military aircraft operating in the Alaska Air Defense Identification Zone (ADIZ) on Tuesday, according to a statement.

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

The ADIZ is a zone that stretches out 150 miles from the U.S. coastline where the U.S. requires aircraft to identify themselves.

NORAD tracks aircraft in the region through a “layered defense network of satellites, ground-based and airborne radars and fighter aircraft,” according to their statement, and they say they remain “ready to employ a number of response options in defense of North America.”

Russia’s defense ministry issued a press release about a long-range training flight by bombers to the Arctic that might offer a description of some of the Russian bombers in this incident saying that two Tu-160 strategic missile carriers performed a flight over the neutral waters of the Arctic Ocean and the Laptev Sea, lasting over 10 hours.

“The flight was carried out in strict accordance with international rules for the use of airspace,” said the commander of long-range aviation, Lieutenant General Sergei Kobylash, whose words were reported to the Russian Ministry of Defense. “Long-range aviation pilots regularly fly over the neutral waters of the Arctic, North Atlantic, Black and Baltic Seas, and the Pacific Ocean.”

Strategic bombers Tu-160, Tu-95MS and long-range bombers Tu-22M3 are part of the long-range aviation of the Aerospace Forces of the Russian Federation. Long-range aircraft are the air component of the Russian nuclear triad, but they can also carry out strikes with conventional missiles and bombs, including cruise missiles, says the Russian Ministry of Defense.

ABC News' Luis Martinez and Lauren Minore contributed to this report.