A Northwest Territories MP is urging Prime Minister Stephen Harper to protect Canada's claim to a disputed area in the Beaufort Sea, where the United States wants to drill for oil and gas.

Dennis Bevington, the NDP member for Western Arctic, expressed concern in the Commons this week that the U.S. and Alaskan governments plan to sell oil and gas exploration leases off the northern coasts of Alaska and the Yukon.

The 21,000-square-kilometre area — roughly four times the size of Prince Edward Island — is claimed by both Canada and the U.S. as part of a territorial dispute spanning more than three decades.

Bevington said Harper should at least demand the issue be settled through diplomatic or even legal means before any drilling takes place.

"The prime minister needs to bring this up at the highest level within diplomatic circles with the United States," Bevington told CBC News.

"If permits are given in the disputed area, those should immediately be taken to the international courts for intervention."

Border over water contested

The two nations have not been able to agree on where to draw a Canada-U.S. border out into the waters of the Beaufort Sea.

Historically, that invisible border has been a straight line extending up the Yukon's western edge, following the 141st parallel out into the sea.

However, the U.S. contends that the border should be redrawn to run perpendicular to the coast, moving the line eastward and giving much of the disputed area to that country.

State officials in Alaska say they are going ahead with offering oil and gas exploration leases in the area but add that the sale might actually force both countries to resolve the dispute.

"If the tract were leased in this lease sale … obviously, we can't sell land that doesn't belong to us, and so there would be actually something the Canadian government and the U.S. government and the State of Alaska would have to discuss," Alaska state oil and gas director Kevin Banks said Thursday.

"There'd be some value here that would be the subject of some discussion."

A state government document sent to potential bidders earlier this month warns oil companies they should be prepared for possible delays in determining title to lands.

Banks said bids are not expected to come in anytime soon because it would be expensive to drill for oil or gas in the Beaufort Sea, and there are no pipelines nearby.

Officials with the federal Department of Foreign Affairs say that although the Beaufort Sea dispute is more than 30 years old, it is being well managed.

However, the government has not specified what it will do to prevent the U.S. from selling oil and gas permits in the disputed area.