Long-range Russian bombers are flying more often and closer to US territory, a top US commander said on Tuesday, as Moscow made its latest show of military might with exercises over the North Pole.
General Gene Renuart, Commander of North American Aerospace Defense Command (NORAD) and US Northern Command, the agencies charged with protecting US and Canadian airspace, said that US forces would continue to monitor the activity.
"Over the last few months the Russian air force has been flying a little bit more than we've seen in the past; certainly they're ranging farther than they have in the more recent past," Renuart said in a statement.
"NORAD has intercepted them out over international waters, near Alaska, and the command continues to monitor all of their long range bomber flight activity, even today," he added.
His comments came as Moscow announced that its strategic bombers had begun exercises over the North Pole and just a week after Russian planes flew within a few hundred kilometers (miles) of a US military base on the island of Guam.
The nuclear-capable bombers in the five days of exercises starting on Tuesday were to practice firing cruise missiles, navigation in the polar region and aerial refueling maneuvers, the Russian air force said in a statement.
One Russian air force officer, who asked not to be identified, told AFP he expected US interceptors would make their presence felt during the exercises.
"It is a traditional practice for military pilots to see foreign pilots come up to meet them and say to hello," he said. "The United States are aware of our exercise," he added.
Last week, several Russian strategic bombers flew over the Pacific to near Guam and, according to a Russian general, exchanged grins with US fighter pilots.
The incident capped a summer in which President Vladimir Putin has sought to project power far and wide, building on a rearmament programme fueled by oil and gas revenues.
"At every opportunity Russia is showing its return to power, including military. It's a demonstration for two audiences domestic and for the rest of the world," Moscow-based analyst Alexander Goltz told AFP last week.
The long-distance flight by the strategic bombers, impossible for years because of severe under-funding, also recalled an incident in July when bombers deployed near Scotland and Norway during a diplomatic row with Britain. And it's not just in the skies that Russia wants the world to take notice.
On August 2 Russian explorers descended 4,261 meters (13,980 feet) under the Arctic to plant a flag on the sea bed and demonstrate in a theatrical fashion Moscow's contested claim to the mineral-rich territory under the North Pole.
The following day, the navy's chief of staff suggested reestablishing a full-time Russian naval presence in the Mediterranean for the first time since the Soviet era.
Meanwhile the ground army, which was badly mauled in more than a decade of fighting Chechen rebels, is getting new equipment and improved training.
"For the Kremlin it's very important to retain at least one area where we equal the United States and we are adamant about showing this," Goltz said.
Russia's generals deny they are up to anything sinister and Russian political commentator Yuliya Latynina said there was nothing to fear from the recent muscle-flexing.
"Thank God. We are showing our strength with bombers, the North Pole flag, etc, but we are not making war," she said.