Gov. Chris Christie says New Jersey won't join a lawsuit supporting the Environmental Protection Agency's new pollution rules.

The rules are designed to decrease smokestack emissions in 27 states that contribute to unhealthy air in other states.

Monday was the deadline to join the suit.

The rules require states to cap and regulate sulfur dioxide and nitrogen oxide, which mostly come from coal-fired power plants. If a facility releases more pollution than allowed, it would either need to install more controls or buy credits from other facilities.

Christie says the state will appeal a ruling by a federal judge who dismissed a lawsuit seeking to shut down a western Pennsylvania coal-burning plant.

Environmentalists question why Christie chose to appeal a lawsuit challenging one plant while refusing to join another suit.