The Obama administration on Friday let stand a Bush-era regulation that limits protection of polar bears from the effects of global warming, saying that a law protecting endangered species shouldn't be used to take on the broader issue of climate change.

Interior Secretary Ken Salazar said that he will not rescind the Bush rule, although Congress gave him authority to do so. The bear was declared threatened under the Endangered Species Act a little over a year ago, because global warming is harming its habitat.

Salazar said rescinding the Bush rule "would provide no more protection for the polar bear and result in uncertainty and confusion about the management of the species."

The iconic bear was declared a threatened species because global warming is causing a severe decline in Arctic sea ice. But the Bush administration rules limit that protection, saying no action outside the Arctic region could be considered a threat to the bear under the law.

Environmentalists have strongly opposed the rule as have many members of Congress. They argued the limits violate the Endangered Species Act because the release of greenhouse gases from power plants, factories and cars indirectly threaten the bear's survival.

But Salazar said the answer to dealing with global warming rests in a broader, comprehensive approach that limits greenhouse gases.

"The Endangered Species Act is not the appropriate tool for us to deal with what is a global issue, and that is the issue of global warming," said Salazar in a conference call with reporters.

In March, federal lawmakers authorized Salazar to scrap the Bush regulation without going through a long regulatory process. The deadline for such action was Saturday, 60 days after Congress acted.

When the Bush administration in March 2008 declared the bear a threatened species, the declaration came with a "special rule" that said no action outside the polar bear's Arctic habitat — such as carbon dioxide emissions from power plants thousands of miles away — could be viewed as detrimental to the bear's survival.

Business groups and their supporters in Congress have argued strongly that the Endangered Species Act is the improper vehicle for addressing climate change and that there are other ways to deal with the global environmental issue.

Congress is trying to craft broad legislation that would limit greenhouse gases and, separately, the Environmental Protection Agency (EPA) has begun a lengthy regulatory process that could lead to heat-trapping emissions being controlled under the federal Clean Air Act. Last month, the EPA declared carbon dioxide from burning fossil fuels and other greenhouse gases a danger to public health.

When the polar bear was declared threatened in 2008, environmentalists hoped they could use the endangered species law to force broader nationwide limits on greenhouse gases.