Off-road engines, ships and aircraft pollute as much as 270 million cars
California and five other US states are set to sue the Environmental Protection Agency (EPA) if it does not act soon to cut pollution, officials say.
Later on Thursday, Californian attorney general Jerry Brown is to launch a lawsuit to "force the EPA into action".
He accuse the EPA of continuing to "wantonly ignore its duty" to regulate greenhouse gases from ships, aircraft, and off-road industrial vehicles.
California sued the US in January to force carmakers to curb emissions.
"Ships, aircraft and industrial equipment burn huge quantities of fossil fuel and cause massive greenhouse gas pollution, yet President Bush stalls with one bureaucratic dodge after another," Mr Brown said.
"Because Bush's Environmental Protection Agency continues to wantonly ignore its duty to regulate pollution, California is forced to seek judicial action."
If the agency fails to issue timely regulations to curb emissions from these vehicles, California will sue the federal government for unreasonable delay, Mr Brown said.
In a letter Mr Brown is to send on Thursday to the EPA, Connecticut, New Jersey, Oregon, the Pennsylvania Department of Environmental Protection and New York City are to join California in the lawsuit, according to a copy of the letter obtained by the Associated Press news agency.
Off-road engines, ships and aircraft emit as much greenhouse gases as 270 million cars, more than the entire number of registered vehicles in the United States, the attorney general said in a press release.
But the agency said it had been "fully responsive" to California's petitions, an EPA spokesman said.
"[The lawsuit] is certainly typical of the attorney general of California," Jonathan Shradar said.
"If they don't like how we make a decision on something, they sue and hope the courts will mandate toward their position. It works sometimes and sometimes it doesn't work," he said.
Mr Brown would be better served lobbying the Democratic-led US Congress to take action, he added.
The states involved in the lawsuit want the EPA to require airlines and ships to use cleaner fuels, to use more fuel-efficient for aircraft or travel at slower speeds for ships, and for off-road vehicles to comply with anti-idling standards.