Russia has formally submitted a revised application to the United Nations for 1.2 million square kilometres of territory in the Arctic. A previous application was rejected in 2002 but Russia claims to have further evidence backing its claim.

"Russia has presented its application to extend its territory on the Arctic continental shelf and it was registered. The work we have done to gather material is extensive," said the Russian Minister for Natural Resources and the Environment Sergey Donskoy, as quoted by Russia Today.

Donskoy said that teams of experts had been working to gather scientific evidence that the Eurasian land mass extends north under the polar ice cap. Under international law, nations may claims exclusive economic rights to the continental shelf extending from its shore.

"From 2002 to 2014, nine geological and geophysical expeditions took place in the central part of the Arctic Basin, using atomic-powered icebreakers, as well as research submarines," Donskoy said.

He said that the UN could begin studying the application this month, and a decision would be made in two to three years' time.

The claim is for 1.2 million square kilometres of underwater space, extending 350 miles from the shore. The Russian Ministry of Natural Resources claim untapped oil and gas reserves in the region may be worth as much as $30tn (£20.7tn).

Canada, Norway and Denmark have all submitted claims to Arctic seabed.

It comes as Russia steps up its military presence in the region, rebuilding a series of Cold War-era military bases and undertaking military exercises. Last week, Russia released a video showing soldiers training in reindeer sleighs mounted with machine guns.