Washington - Under the pressure of a court-ordered deadline, the United States Wednesday classified the polar bear as a threatened species because of global warming and rapidly melting Arctic ice.

In the surprise decision, US Secretary of the Interior Dirk Kempthorne said the decision was prompted by the prospect that the polar bear could become endangered within
45 years, a status that would mean it is facing extinction.

But Kempthorne also warned that he would make sure the decision will not be used as a back door to regulate US policy on climate change, saying the decision would be carried out in such a way "to protect the polar bear while preventing unintended harm to society and the economy of the United States."

"The sea ice is vital to the polar bear's survival," Kempthorne said. "The polar bears' sea ice habitat has drastically melted."

He said that computer projections, which he hoped would turn out wrong, currently anticipated further rapid melting around the Arctic polar cap. (dpa)