About 100 fighter jets and 4,000 personnel from the United States and eight European nations began an Arctic training exercise in the Nordic nations on May 25.
The exercise, based in the north of Norway, Sweden and Finland, aims to test cooperation among Arctic nations near Russia.
The exercise, lasting from May 25 to June 5, was planned before Moscow's annexation of Ukraine's Crimea region last year raised regional tensions.
Norwegian Brigadier General Jan Ove Rygg, who is heading the exercise, said in a statement, "The aim is to exercise and train units in the orchestration and conduct of complex air operations, in close relations to NATO partners."
The manoeuver is one of the largest exercise involving fighter jets in Europe this year and the second of its type after one in 2013.
NATO members involved were the United States, Germany, Britain, France, the Netherlands and Norway, as well as nonmembers Sweden, Finland, and Switzerland, which are linked to the alliance via NATO's partnership for peace.
Russia has stepped up military activity around the Nordic and Baltic region.
Meanwhile, Russian Deputy Prime Minister Dmitry Rogozin has dismissed Western concerns over Moscow's increased assertiveness in the Arctic by saying that "tanks don't need visas."
Dmitry Rogozin, who oversees the defense industry, is known for his hawkish remarks.
Rogozin told state television late May 24, after the host asked him whether Europe and the United States are concerned about Russia's presence in the Arctic, "I've always joked about it... so what if they won't give us visas, put us on sanctions list... tanks don't need visas."
Russia has also conducted huge military exercises in the Arctic region.
Rogozin, who formerly served as an envoy to NATO, is on the sanctions list of both the U.S. Treasury and the European Union following Russia's annexation of Crimea in March 2014.
Last May his plane was prevented from flying over EU member Romania, after which he wrote: "Next time I will fly in a Tu-160" bomber, provoking protest from the Romanian Foreign Ministry who called it a "serious threat."