Within the Arctic circle there are 90 billion barrels of oil and vast quantities of natural gas waiting to be tapped, most of it offshore, the government-run US Geological Survey (USGC) said.

The top of the world, shared by half a dozen countries including the US, Russia, Canada, Sweden, Norway and Greenland, holds an estimated 90 billion barrels of crude, 1,670 trillion cubic feet of gas and 44 million barrels of natural gas liquids, the USGS said in a report.

84 per cent of that potential energy resources is expected to lie offshore, said the report, which comes a week after the US government lifted a 17-year ban on offshore drilling hoping to ease a spiraling fuel price crisis.

"The resources account for about 22 per cent of the undiscovered, technically recoverable resources in the world," the USGS said, meaning the estimated volume is not added to the world's known recoverable resources.

The Arctic estimate, said USGS geologist Donald Gautier, includes some degree of uncertainty.

Broken down, the Arctic energy reserves would account for about 13 per cent of the undiscovered oil, 30 per cent of the undiscovered natural gas, and 20 per cent of the undiscovered natural gas liquids in the world, the report said.

The majority of the undiscovered 90 billion barrels of crude oil, USGS experts estimate, are lying in Alaska, where 30 billion are hiding, Russia's Barents Basins, East and West Greenland and East Canada.

"The Alaska platform really looms as the most obvious place to look for oil in the Arctic right now," said Gautier.

Some 40 billion barrels of oil and 1,100 trillion cubic feet of gas have already been found in the Arctic region.

By comparison, US oil reserves stand at 22 billion barrels, and its production level at 1.6 billion barrels per year.

Across the world, proven oil reserves stand at a record 1.24 trillion barrels. Production is stable but consumption some 30 billion barrels per day is on the rise.

The natural gas the Arctic region is estimated to hold, 1,670 trillion cubic feet, is potentially a more important find since it would represent nearly one third of all the undiscovered gas reserves in the world.

Most of the untapped gas reserves in the Arctic region (70 per cent) lie in the West Siberian Basin and East Barents Basin, in Russia, and Arctic Alaska, the USGS said.