SACRAMENTO, Calif. (AP) — Five states intend to sue the Environmental Protection Agency if it does not act soon to reduce pollution from ships, aircraft and off-road vehicles.

In a letter that California Attorney General Jerry Brown was to send Thursday to the EPA, the five states and New York City accuse the Bush administration of ignoring their requests to set restrictions.

"It's a necessary pressure to get the job done," Brown said Wednesday in an interview with The Associated Press. "The issue of reducing our energy dependence and greenhouse gas emissions is so challenging and so important that we have to follow this judicial pathway."

The threatened lawsuit comes as California is challenging the EPA in federal court over its decision last year to prohibit the state from imposing its own emission standards on vehicles.

Brown's letter announces the group's intent to sue, a procedural step required six months before filing a lawsuit. Connecticut, New Jersey, Oregon, the Pennsylvania Department of Environmental Protection and New York City will join California in the lawsuit, according to a copy of the letter obtained by the AP.