Russia is denying that one of its aircraft approached Canadian airspace three days before U.S. President Barack Obama visited Ottawa on Feb 19.

Canadian Defence Minister Peter MacKay said Friday that Canadian CF-18 fighter jets at Cold Lake, Alta., scrambled to intercept the plane on Feb. 16 after North American Aerospace Defence Command (Norad) detected the Russian Bear long-range bomber headed for Canada.

The aircraft never did enter North American airspace.

MacKay confirmed the incident at a news conference in Ottawa with the chief of the defence staff, Gen. Walter Natynczyk, and the commander of Norad, Gen. Gene Renuart.

However, Russian Defence Ministry spokesman Alexander Drobyshevskiy said Friday the planned flight of the Russian long-range strategic aircraft was part of "regular military training and air patrol plans in the northern latitudes.

"All the international flights regulations were strictly respected," he said in a statement. "Therefore, the very possibility of a violation of Canadian airspace is out of [the] question. The adjacent countries were informed of that flight in good time."

A Canadian F-18 was one of the fighter jets dispatched to intercept a Russian plane. (Franco De Bernardi/Associated Press)

Yevgeniy Khorishko, a spokesman at the Russian Embassy in Washington, also appeared to downplay the incident.

"It was a routine flight over international airspace," he told CBC News.

Obama arrived in Ottawa on Feb. 19 to meet with Prime Minister Stephen Harper. He spent six hours in the nation's capital.

MacKay told reporters he wasn't accusing Russia of deliberately timing the flight to coincide with the visit — when Canadian security was focused in Ottawa — but he did call it "a strong coincidence, which we met with … CF-18 fighter planes and world-class pilots that know their business."

"[The pilots] sent a strong signal they should back off and stay out of our airspace."

Speaking in Saskatoon, Prime Minister Stephen Harper said Friday that Russian intrusions into Canadian airspace are "a real concern," but that Canada would defend its sovereignty.

"I have expressed at various times the deep concern our government has with increasingly aggressive Russian actions around the globe and Russian intrusions into our airspace," Harper told reporters.

"We will defend our airspace, we also have obligations of continental defence with the United States. We will fulfil those obligations to defend our continental airspace, and we will defend our sovereignty and we will respond every time the Russians make any kind of intrusion on the sovereignty in Canada’s Arctic."

Russian aircraft regularly probed into North American airspace during the Cold War, and Canadian and American fighters routinely tracked the snoopers and escorted them back into international airspace.

Such flights were suspended for years after the collapse of the Soviet Union, but resumed in recent years as Russia pushed its claim on the Arctic and oil wealth allowed the country to spend more on its military.

MacKay said Canada has seen "increased activity" in recent years.

Canadian officials told CBC News the latest incident is the 20th time in the past two years that Russian bombers have approached Canadian airspace and been turned away.

Norad spokesman Michael Kucharek wouldn't say what signals the pilots sent to the Russians, but did say they were close enough to make visual identification.

"Visual identification is enough to get their attention," he said.

Kucharek said it's possible the Russian plane was taking part in a military exercise.

"These types of exercises occur and have occurred over the past few years in quite a few different times and places."

Rival Arctic claims

Melting Arctic ice has increased the chances of a standoff between countries that claim a stake in the region. The Arctic seabed, an area as large as the Prairie provinces, could be abundant in natural resources such as oil and gas.

The region is currently divided among Canada, the United States, Norway, Russia and Denmark.

Countries that ratified the United Nations Convention on the Law of the Sea have 10 years to prove their continental shelves extend beyond the 370-kilometre (200-nautical-mile) outer limit currently in place. Since Canada ratified the convention in 2003, it has until 2013 to submit scientific evidence to extend that limit.

Russia claims the Arctic seabed and Siberia are linked by the same continental shelf. The UN rejected the claim, citing lack of evidence, but the country is set to resubmit the application in 2009.

Harper has said Arctic sovereignty is a key priority of his government and has promised to beef up Canada's military presence in the region. The Tory government has also moved to increase the jurisdiction of Canadian environmental law over northern waters and made it mandatory for vessels there to register with the Canadian Coast Guard.

Canadian scientists are mapping the seabed in an effort to bolster Canada's claim.

Two years ago, Russia sent a mini-submarine to plant a flag on the ocean floor at the North Pole.

MacKay, who was foreign affairs minister at the time, scoffed at the move, saying: "You can't go around the world these days dropping a flag somewhere. This isn't the 14th or 15th century."

With files from the Canadian Press