Denmark has sent a research team to the Arctic ice pack to seek evidence that the Lomonosov Ridge underwater mountain range is attached to the Danish territory of Greenland.
The research team, with specialists from Canada, Denmark and Sweden, set off on Sunday (12 August) from Tromsoe in northern Norway on board the Swedish ice-breaker Oden. They will return to Norway's Svalbard islands on 17 September.
Canada, Russia, the US and Norway have also claims in the Arctic region, where the US Geological Survey has suggested as much as 25 percent of the world's undiscovered oil and gas could be hidden.
The race for the Arctic is also intensifying because global warming is shrinking the polar ice cap, which could some day open for new shipping lanes linking the Atlantic and Pacific oceans.
Russia believes the Lomonosov Ridge underwater feature is linked to its Siberian territory and made a submission to the United States as early as 2001 claiming sub-sea rights stretching to the Pole.
To back up the claims, members of Russia's parliament watched from a mini-submarine when their country's flag was planted on 2 August four kilometres (2.5 miles) below the North Pole.
The meter-high flag is made of titanium so as not to rust, said Russian news agency ITAR-TASS.
The move was treated with derision by Canadian foreign minister Peter MacKay who likened it to tactics used in the 15th Century, the BBC reported.
Canada itself has just started Arctic sovereignty claims with prime minister Stephen Harper announcing last week plans to build an army training centre and a deep-water port at Nanisivik near the eastern entrance of the Northwest Passage to help refuel its military patrol ships.
Ottawa also plans to buy at least six new patrol ships for the area.
Washington has sent a coast guard cutter on a mapping mission to the Arctic this week to determine whether part of the area can be considered US territory. It is the third US Arctic mapping cruise since 2003.
The North Pole seabed is not currently regarded as part of any single country's territory and is governed instead by complex international agreements.
Danish claims for the areas go via Greenland. Although part of the Danish Realm, Greenland is not a part of the European Union.
A visit to Greenland by European Commission president Jose Barroso in June was largely focussed on climate change but also included signature of an EU-Greenland partnership deal.