Canadian Prime Minister Stephen Harper has said Canada has taken its sovereignty in the Arctic region too lightly for too long.

Mr Harper was speaking during a three-day tour of Canadian territory in the Arctic.

His comments come a week after a Russian submarine crew planted their national flag on the ocean floor at the North Pole.

The Russian vessel reached a depth of 4,261m to carry out scientific tests.

Mr Harper said his government was putting a big emphasis on re-enforcing its sovereignty.

Describing the Arctic as a 'largely untamed, sometimes harsh and always magnificent' region, he vowed to protect Canada's interests.

Canada is at odds with Russia, Denmark, Norway and the US over 1.2m square kilometres of Arctic seabed, thought to hold 25% of the world's undiscovered oil and gas reserves.

International rivalry in the region has heated up as energy reserves grow scarce in other parts of the world and as melting polar ice caps make the area more accessible to research and economic activity.

Meanwhile, US President George W Bush has been pushing Congress to ratify an international pact to allow Washington to submit scientific data to the UN in pursuit of its own claim.