MOSCOW, Saturday, Aug. 18 — President Vladimir V. Putin said Friday that the Russian Air Force would begin regular, long-range patrols by nuclear-capable bombers over the world’s oceans, resuming the practice after a 15-year hiatus in another sign of Russia’s growing assertiveness.

In the first flight, 14 bombers and six supporting airplanes took off at midnight on Friday, Mr. Putin said, in remarks carried on state television. Mr. Putin said such patrols would continue “from this day on.”

The sortie on Friday included Tu-160 and Tu-95 airplanes, known by their NATO appellations as Blackjacks and Bears, according to a statement posted on the Russian Defense Ministry Web site.

The Russian bombers were flying Friday over the Atlantic and Pacific Oceans and the North Pole, and were being escorted by NATO fighter jets, the site said, recalling the standoffs of the cold war.