The Environmental Protection Agency said Tuesday that it is hammering out details with states on implementing the Obama administration's 2015 rule for ozone pollution, as environmental groups railed against EPA Administrator Scott Pruitt for missing Monday night's legally enforceable deadline for meeting the regulations.

The agency is "continuing to work closely with the states to work through the designations process for the 2015 ozone standard," said EPA spokeswoman Liz Bowman in an email to the Washington Examiner.

A number of environmental groups, after hearing no official word from the agency, began criticizing the agency, saying it is legally obligated to meet the rules by issuing specific information on which areas of the country exceed the pollution standards and must develop strategies to comply with the caps.

Ozone is a component of smog that is blamed for causing asthma and other respiratory problems.

"Since they did not release any information like they were supposed to, we are very concerned given the Trump administration's record they will not enforce this law and try to repeal it," the Sierra Club said.

The EPA had attempted to delay the rules by one year, but a court ruling forced the agency to continue with the regulations. The EPA agreed to abide by the end of Monday.

Bowman's statement suggests that the agency thinks it's is fine to continue deliberating with states on which areas would exceed the standards, which critics say are so strict that many of the U.S.' park lands, which have no industry, would not be able to comply.

Manufacturers and the oil industry argue that most states have not met the 2008 rules for cutting ozone and should be allowed to do that before stricter regulations are imposed. The manufacturers say the strict ozone rules would limit development and economic growth in many of the nation's regions, especially its metropolitan areas.