"The total flight time exceeded 12 hours", the ministry added.
The North American Aerospace Defense Command said in a statement that its early warning system identified the four Tupolev Tu-95 bombers and two Su-35 fighters.
"2x Tu-95s were intercepted by 2x F-22s; a second group of 2x Tu-95+2x Su-35 was intercepted later by 2 more F-22's; NORAD E-3 provided overall surveillance", NORAD's official account tweeted.More news: Windows 10's May patches are borking McAfee and Sophos software
They were picked up as they entered the Alaska Air Defense Identification Zone, a perimeter line that lies outside national airspace but within which air traffic is kept under constant surveillance to reduce response times in case of a hostile threat. The Russian aircraft remained in global airspace. O'Shaughnessy, commander of NORAD, in a statement on Monday's incident.
Russian military officials acknowledged the incursion into US airspace, saying the aircraft were conducting "scheduled sorties" in global airspace near the country's borders.
A total of six Russian aircraft were intercepted by United States fighter jets off the coast of Alaska on Monday, officials with North American Aerospace Defense Command said in a statement. "We are on alert 24 hours a day, seven days a week, 365 days a year", Air Force General Terrence J. All civilian craft entering the zone must identify themselves.More news: Baby cut from murdered mother's womb opens his eyes in NICU
Russian Federation said that its long-range aircraft regularly perform flights over the worldwide waters of the Arctic, the Atlantic, the Black Sea and the Pacific Ocean.
U.S. officials say Russian bombers and jets have flown in the area several times a year for the last few years and have similarly been intercepted by U.S. or Canadian jets operating as part of NORAD.
Russia's defense ministry said that the flights are performed in strict compliance with the worldwide rules of using the airspace, without violating the borders of other states.More news: Alabama Public Television Won't Air "Arthur" Episode Featuring Gay Wedding