With the possibilities presented by global warming, the Canadian Government is experiencing new challenges to its claims of sovereignty to territories as far as the North Pole which, of course, would include the Northwest Passage. Canada's claim has roused several national governments, particularly Russia and Denmark (by reason of Greenland) as well as the United States. Canada's perspective is that they have full sovereignty encompassing the islands/waterways and thereby will assert complete control over all activity in that specific region, in accordance with the general principles defined in UNCLOS (United Nations Convention on the Law of the Sea), based on the rules concerning determination of baselines in the archipelagic context defined in Part IV. The Canadian Government has continually stated that it does support international shipping through the Northwest Passage, provided that Canadian domestic laws, rather than international law, are followed. In July 2007, Prime Minister Stephen Harper reinforced the Canadian position by announcing the construction of up to eight Polar Class 5 Arctic Offshore Patrol Ships and the establishment of a deep-water port in the far north; in this way, they intended to enforce Canadian sovereign laws, including criminal accountability for the Master's negligence.