The political temperature in the Arctic rose on Tuesday when Vladimir Putin vowed to step up Russia's military presence in the region in response to a claim by Canada to the north pole.

In typically trenchant style, the Russian president told his defence chiefs to concentrate on building up infrastructure and military units in the Arctic. He said the region was again key to Russia's national and strategic interests, following a retreat in the post-Soviet period.

His comments were a direct and rapid riposte to Canada, a rival Arctic power. On Monday Canada's foreign minister, John Baird, said his government had asked scientists to work on a submission to the UN arguing that the outer limits of Canada's territory include the north pole, which has yet to be claimed by any country.

The submission will further assert that Canada owns the Lomonosov Ridge, an undersea mountain range between Ellesmere Island, Canada's most northern landmass, and Russia's inhospitable east Siberian coast. Russia insists that it is the ridge's true owner. In 2007 Russian scientists carried out a mission to the region and came back claiming the shelf for the Russian Federation. Divers even planted a flag on the seabed.

Last week Canada applied to the UN commission on the limits of the continental shelf to increase its nautical borders. Currently the five nations with territories near the Arctic circle – Canada, Denmark, Norway, Russia and the US – are allotted 200 nautical miles from their northern coasts. Canada is seeking to extend its territory by about half a million square miles .

Russia made a similar claim in 2001. The commission is unlikely to come to a definitive conclusion for some time: resolution is only possible with the agreement of the countries involved, a process that could drag on for years and probably decades. In the meantime Canada and Russia have been stepping up their military footprint in the oil- and gas-rich region. Putin has said Russia will restore Arctic bases that fell into disrepair after the collapse of the Soviet Union, including one on the New Siberian Islands. On Tuesday he said this base and others were crucial to protecting Russia's "security and national interests".

Canada pole claim

Russia's renewed interest in the region coincided with Putin's ascent to the Kremlin in 2000. Between 2009 and 2011, under Dmitry Medvedev, Russia adopted a more conciliatory policy. It resolved a dispute in the Barents Sea with Norway and agreed a new search and rescue policy with other Arctic powers. Latterly, however, Putin's Arctic rhetoric has been hawkish.

Canada's conservative prime minister, Stephen Harper, likewise has vociferously asserted his country's right to the Arctic. According to the US geological survey, the region contains 30% of the world's undiscovered natural gas and 15% of its oil. It also has lucrative shipping routes.

"It's often said that the Russians act with their Arctic policy in an aggressive, nationalistic and unilateral way. The same thing can be said about the Canadians," said Andrew Foxall, director of the Russian Studies Centre at the Henry Jackson Society. "Harper has said Canada is an Arctic nation. He frequently goes up into Canada's high Arctic. There are large-scale military exercises there." In 2010 Canada declared that Santa was a Canadian citizen.

Some experts have described Canada's audacious claim to the north pole as a long shot. This week Baird said it would take several years for Canada to map the continental shelf and to complete its full UN submission. "We are determined to ensure that all Canadians benefit from the tremendous resources that are to be found in Canada's far north," he said.

The Canadian media reported that Harper personally insisted the north pole be included in any new claim even though the scientific evidence put Canada's boundary just south of it. The Arctic has been a popular domestic issue for the prime minister, who has talked of his country's northern national identity.

Michael Byers, an expert on Arctic and international law at the University of British Columbia, said the planned UN submission was clearly political. "[Harper] does not want to be the prime minister seen publicly as having surrendered the north pole, even if the scientific facts don't support a Canadian claim," he said. "What he's essentially doing here is holding this place, standing up for Canadian sovereignty, while in private he knows full well that position is untenable."

Byers said the claim covered some of the most remote and harshest places on the planet, and commercial exploitation of resources was a long way off. "We're talking about the centre of a large, inhospitable ocean that is in total darkness for three months each year, thousands of miles from any port," he said. "The water in the north pole is 12,000ft [3,650 metres] deep and will always be covered by sea ice in the winter. It's not a place where anyone is going to be drilling for oil and gas. So it's not about economic stakes, it's about domestic politics."

Phil Steinberg, director of the International Boundaries Research Unit at Durham University, said that in practice Canada and Russia co-operated with each other. Their rhetoric over the Arctic was politically charged but scientists from the rival states were working closely together to map the frozen region. The north pole, meanwhile, was not home to untold oil and gas riches, he said. "It's more a symbol of national pride," he suggested.