WASHINGTON — The Bush administration has decided to propose listing the polar bear as threatened under the Endangered Species Act, putting the American government on record as saying that global warming could drive one of the world’s most recognizable animals out of existence.

The administration’s proposal — which was described by an Interior Department official who spoke on condition of anonymity — stems from the fact that rising temperatures in the Arctic are shrinking the sea ice that polar bears need for hunting. The official spoke on condition of anonymity because the department will submit the proposal today for publication in the Federal Register, after which it will be subject to public comment for 90 days.

Identifying polar bears as threatened with extinction could have an enormous political and practical impact. The polar bear occupies an important place in the American psyche. Because scientists have concluded that carbon dioxide from power plant and auto emissions is helping drive climate change worldwide, putting polar bears on the endangered species list raises the legal question of whether the government would be required to compel American industries to curb their carbon dioxide output.

“We’ve reviewed all the available data that leads us to believe the sea ice the polar bear depends on has been receding,” said the Interior official, adding that U.S. Fish and Wildlife Service officials have concluded that polar bears could be endangered within 45 years.