The USGS says the area has three times as much untapped natural gas as oil.

Drilling plans in the Arctic have been controversial, with environment groups worried about the effect on wildlife.

While oil prices have been falling in recent days to around $125 a barrel, many analysts expect oil prices to remain high, and to rise again. <!-- E SF -->

The figures from the USGS are said to be the first estimate of the petrol available north of the Arctic circle. <!-- S IBOX -->

According to the survey, the Arctic holds about 13% of the world's undiscovered oil, 30% of the undiscovered natural gas, and 20% of the undiscovered natural gas liquids.

"Before we can make decisions about our future use of oil and gas and related decisions about protecting endangered species, native communities and the health of our planet, we need to know what's out there," said USGS director Mark Myers.

US President George W Bush has already urged Congress to end a 27-year ban on drilling for oil in US coastal waters, to make the US less reliant on imports.

Exploration companies believe the recent rapid ice melt in the Arctic may make it easier to get reserves out of the region.