A new fight emerged Friday between states and the Environmental Protection Agency over whether the Obama administration can still work with states on its climate rules during a Supreme Court stay.

Attorneys general representing 29 states suing the EPA over its climate rules, called the Clean Power Plan, sent a letter to the heads of associations representing state utility and air regulators advising them that states are under no legal obligation to continue to work with the administration on compliance plans.

"We want to ensure that states understand that there is no legal obligation to continue to spend taxpayer funds on compliance efforts and that, in the unlikely event the Power Plan is ultimately upheld by the courts more than a year from now, there will be ample time then to restart those efforts," attorneys general Patrick Morrisey of West Virginia and Ken Paxton of Texas wrote in the letter.

The attorneys general were responding to news reports that EPA Administrator Gina McCarthy met with a group of state regulators in Washington on Thursday, encouraging them to continue working on compliance with the Clean Power Plan despite the stay.

"We understand that your organizations have been engaged in significant discussion about the meaning of the stay for the states, and heard yesterday from EPA Administrator Gina McCarthy, who urged states to continue to take voluntary steps toward compliance with the Clean Power Plan," the letter says. The attorneys general say that it is simply not warranted to continue working and that EPA should stop.

"We believe the court's decision to grant the stay for the duration of the litigation — including any Supreme Court review — means that the states, their agencies and EPA should put their pencils down," the letter reads. "Any taxpayers dollars spent during the judicial review process are unnecessary and likely to be entirely wasted."

The conservative group American Energy Alliance had a similar message to states on Thursday. The group issued a "stop work" message to governors of all states, utility and environmental regulators to cease all work on compliance with the climate regulation.

The Clean Power Plan requires states to cut greenhouse gas emissions a third by 2030. The 29 states suing argue that the plan violates the Constitution by giving EPA authority over their resource and energy planning. States had been developing compliance plans to meet the rule's first deadline in September.