WASHINGTON - President Bush responded yesterday to a Supreme Court ruling by ordering federal agencies to find a way to begin regulating vehicle emissions by the time he leaves office.

In a Rose Garden announcement, Bush said he wanted to move ahead, pending any separate legislative approaches. The new rules will "cut gasoline consumption and greenhouse gas emissions from motor vehicles," he said.

But the Bush executive order telling several agencies to finish the work by 2008 also said they must take into account the views of the general public, the impact the new rules would have on safety, scientific knowledge, available technology, and the cost. Bush's term ends Jan. 20, 2009.

"This is a complex legal and technical matter and it's going to take time to fully resolve," he said.

Last month, the Supreme Court rebuked the Bush administration for its inaction on global warming. In a 5-4 decision, it declared that carbon dioxide and other greenhouse gases qualify as air pollutants under the Clean Air Act and thus can be regulated by the Environmental Protection Agency.

The court also said that the "laundry list" of reasons the administration has given for declining to do so are insufficient, and that the EPA must regulate carbon dioxide, the leading gas linked to global warming, if it finds that it endangers public health.

Democrats who control Congress have been pressuring the administration to say when it will comply with the high court's ruling and decide whether to regulate carbon dioxide.

Bush has said previously that he recognizes the serious environmental problems created by such emissions and other so-called greenhouse gases. But he has urged against anything other than a voluntary approach, saying regulations could undercut economic activity.

White House press secretary Tony Snow said the president's position has not changed. "The market-based approach seems to work," Snow said. "The question is: Do you try to set up a mandatory system or do you try to set up an innovation-based system? The president prefers innovation."

The environmental group Environmental Defense said the effort "will fall far short of fixing the climate problem" without mandatory caps on carbon emissions.