What's Russia doing that Canada and Denmark are not?

Northern Canada - Wikipedia, the free encyclopedia
Since 1925, Canada has claimed the portion of the Arctic between 60°W and 141°W[1] longitude, extending all the way north to the North Pole: all islands in this region are Canadian territory and the territorial waters claimed by Canada surround these islands. Views of territorial claims in this region are complicated by disagreements on legal principles. Canada and the USSR/Russia have long claimed that their territory extends according to the sector principle to the North Pole. The United States does not accept the sector principle and does not make a sector claim based on its Alaskan arctic coast. Claims that undersea geographic features are extensions of a country's continental shelf are also used to support claims; for example the Denmark/Greenland claim on territory to the North Pole, some of which is disputed by Canada.