The top U.S. environmental regulator on Friday declined to make rules to regulate planet-warming emissions under existing pollution laws despite a Supreme Court decision that has pressured his agency to act.

Environmental Protection Agency Administrator Stephen Johnson said Congress should make rules to regulate emissions of carbon dioxide and other gases blamed for global warming.

U.S. lawmakers said the Bush Administration has saddled the next president with the responsibility of rule-making. A proposed U.S. climate bill died last month in the Senate.

Last year's Massachusetts v. EPA Supreme Court ruling had found that greenhouse gases can be regulated under the U.S. Clean Air Act. The decision pressured the EPA to reconsider its refusal to regulate carbon dioxide emissions from new cars and trucks.

But instead of laying out rules, Johnson solicited public comments for a 120-day period on a nearly 1,000 page draft on the effects of climate change and the ramifications of the Clean Air Act on greenhouse emissions.

"If the nation is serious about regulating greenhouse gases the Clean Air Act is the wrong tool for the job and it's really at the feet of Congress to come up with good legislation that cuts through what will likely be decades of regulation and litigation," Johnson told reporters in a teleconference.

The White House said in a statement that the "onerous command-and-control regulation contemplated in the EPA staff draft would impose crippling costs on the economy in the form of a massive hidden tax, without even ensuring that the intended overall emissions reductions occur."

In March, the EPA started writing regulations for emissions from cars and stationary sources like power plants. But Johnson said Congress could make rules faster than the agency.

He said the time it would take to regulate greenhouses gases under the Clean Air Act would be akin to walking across the entire country, while getting Congress to make rules would be like traveling on a supersonic jet.

RECKLESS

Lawmakers from both parties said the administration had delayed needed action on global warming.

"The deliberate efforts to delay adherence to the Supreme Court's decision is reckless and irresponsible," Sen. Olympia Snowe, a Maine Republican, said in a release,

"After more than seven years, this administration is still not willing to make the hard choices to confront global warming," Sen. Tom Carper, a Delaware Democrat and chairman of the Senate Subcommittee on Clean Air and Nuclear Safety, said in a release.

The delay gives some car-makers, electric utilities and oil refiners time to prepare for changes in their products and plants that could cost them billions of dollars.

The Alliance of Automobile Makers said the Clean Air Act "does not include all of the tools and criteria needed to address the global issue of climate change, including requirements to balance the economic effects and impacts on U.S. manufacturing jobs along with the environmental considerations."

Both U.S. presidential candidates say they support regulating greenhouse gases with the help of market mechanisms such as cap and trade.