A U.S. Interior Department source, who did not want to be identified, told The Washington Post that the government would soon make the request public in the Federal Register, opening the door to hearings.

The filing will just meet a 2-year deadline in response to lawsuits from three environmental groups that claimed the government was dragging its feet on the animals' status, The Post said.

The filing acknowledges global warming is responsible for rapid loss of Arctic sea ice, which the bears use as a living and feeding platform. U.S. Fish and Wildlife Service officials have warned polar bears could be endangered within 45 years as the Arctic ice recedes.

Scientists say there are 20,000 to 25,000 polar bears in 19 separate populations worldwide, about 4,700 of which live in Alaska. Canada, Russia, Denmark (Greenland) and Norway have the balance.