According to Polar Bear's International, "about 60% of the world's polar bears live within or are shared by Canada. Polar bears are also found in the U.S. (Alaska), Russia, Greenland, and Norway (Svalbard)."
Currently, the only real threat to polar bears is climate change. The IUCN lists the polar bear as a vulnerable species, citing sea ice losses from climate change as the single biggest threat to polar bear survival. Polar bears rely on the sea ice to hunt, travel, breed, and sometimes to den.
The population of polar bears is declining.
Canada's Western Hudson Bay population has experienced a 22% decline or greater since the early 1980s, and the Southern Beaufort Sea population along the northern coast of Alaska and western Canada have plunged by about 40% over a 10-year study period from 2001-2010 (polarbearsinternational.org).
"In the Canadian Arctic, adult female polar bears with cubs hunt about 19% of their time during the spring and about 38% of their time during the summer. Adult male polar bears hunt about 25% of their time during the spring and about 40% of their time during the summer" (seaworld.org).