LITTLE ROCK — Environmental Protection Agency Administrator Scott Pruitt announced Wednesday that states will have an extra year to comply with new ozone pollution standards, a delay that Arkansas Attorney General Leslie Rutledge called necessary and the Sierra Club of Arkansas called illegal.

Also Wednesday, Rutledge joined a 16-state coalition calling on President Donald Trump to ease federal regulations on states and encourage compromise between the federal and state governments.

An EPA rule issued in 2015 during former President Barack Obama’s presidency lowers the limit on ground-level ozone from 75 parts per billion to 70 parts per billion. Rutledge challenged the rule in a lawsuit filed in October 2015 along with Arizona, North Dakota, Oklahoma and the New Mexico Environmental Department.

“Administrator Pruitt has made the right decision by extending this initial deadline for the states,” Rutledge said in a statement Wednesday. “Arkansans take great pride in our clean air, and the state has continually improved its air quality, but the burdensome and costly ozone regulation makes compliance nearly impossible while placing great financial strain on small, rural communities.”

Glen Hooks, director of the Arkansas chapter of the Sierra Club, said the Trump administration is “prioritizing polluters over public health.” He said smog caused by ozone pollution is a significant cause of early deaths, heart disease, lung disease and asthma, and that the EPA rule is intended to protect people from pollution caused by coal-burning power plants like ones in Arkansas.

“The Sierra Club fought hard to secure stronger ozone protections, and we will continue to fight today’s illegal flouting of the Clean Air Act. The right of every Arkansan to breathe clean air is is too important to ignore,” Hooks said.

Led by Texas, 16 states’ attorney generals wrote to Trump on Wednesday that “the existing regulatory approach presents an enormous problem for private individuals, businesses, and state attorneys general, irrespective of political affiliation.”

“When federal agencies have virtually full control over the law, power is concentrated at the federal level. And the party that controls the executive effectively runs the nation — from what’s taught in the nation’s schools to the way our businesses are managed,” the group wrote.

In addition to Texas and Arkansas, states signing onto the letter were Alabama, Arizona, Indiana, Kansas, Louisiana, Missouri, Nebraska, Nevada, Oklahoma, South Carolina, South Dakota, Tennessee, West Virginia and Wisconsin.