Russian naval aircraft repeatedly buzzed a U.S. warship last week in a Cold War-style incident that U.S. Navy's chief of operations has raised with his Russian counterpart. The USS Taylor did not go on an alert over unusually close encounters on Sept. 10 and Sept. 11 in international waters of the Barents Sea, just off Russia. "The ship did not take this as hostile," Reuters quoted Col. Dave Lapan as saying. The U.S. warship had just completed a port visit to the Russian city of Murmansk to honor World War Two veterans of both countries. The next day, on Sept. 10, a Russian maritime patrol aircraft flew just 50 yards (45 metres) off the USS Taylor and only 100 feet (30 metres) above sea level -- extremely close and low. It also flew directly over the ship but at an altitude of about 2,000 feet (610 meters). The next day, a Russian ship in the vicinity had one of its Helix helicopters fly by the USS Taylor, again just 50 yards off the U.S. warship and only 100 feet above sea level. "Both sides are in discussions now to determine whether the proper protocols were followed," Lapan said. "This is a fairly rare occurrence." The U.S. Navy's chief of operations, Admiral Gary Roughead, raised the matter with his Russian counterpart, Admiral Vladimir Vysotskiy, during a visit on Wednesday by a top-level Russian defense delegation to the Pentagon. "Admiral Roughead was satisfied after having this conversation with his counterpart," Lapan said without elaboration. A year ago, two nuclear-powered Russian submarines patrolled off the Eastern Seaboard in what U.S. officials speculated was an effort by Moscow to show a greater military presence.