State attorneys general called on all states Wednesday to cease all activity on meeting the goals of President Obama's far-reaching climate rules for power plants, given Tuesday night's decision by the Supreme Court to stay the regulations.

West Virginia Attorney General Patrick Morrisey, who is leading 29 states in a fight against the regulations, said on a call with reporters that the decision by the Supreme Court's five conservative justices was "historic," freezing Obama's "illegal Clean Power Plan" and lifting all obligations to meet their deadlines until a federal appeals court makes a decision on the merits later this year.

"Don't let them [the administration] spin out of this, this is a very significant win," he said.

The Clean Power Plan is the centerpiece of the president's agenda to fight climate change. The plan requires states to cut their greenhouse gas emissions a third by 2030, which the 29 states argue is an unconstitutional imposition of the federal government on states. The White House said Tuesday night that it will continue to work with states on compliance, downplaying the court's decision as procedural.

Morrisey said all states, even those that support the administration's plan, are obligated under the court's decision to stop all activity related to complying with the plan's goals. The Environmental Protection Agency requires states to begin filing plans on meeting the plan's goals, or ask for extensions, beginning in September.

A number of state utility and environmental regulators, with governor-appointed energy officials, were in Washington to hold a two-day meeting on Clean Power Plan compliance when the decision came down from the court. Morrisey said it is a waste of state resources for them to continue their planning with a stay in place.

"States and utilities are not required to prepare a plan," Morrisey said. He added that the need to change state laws and energy portfolios to comply with the emission regulation "are stayed as well." The court's decision says "put down your pencils because EPA has no authority," he said.

EPA Administrator Gina McCarthy is slated to address the regulators Thursday.

Morrisey told reporters on the call that the court's decision gives states the confidence they will prevail on the merits of their case in the D.C. Circuit Court of Appeals, which is scheduled to hear the case in June. He said the justices would have never halted the rule if they didn't believe the chances are high the states will win on the strength of their arguments.

The EPA told the court just days before the decision that for justices to agree to a stay would be unprecedented, given the high court's long precedent of not ruling on cases before a court has made a decision on the merits of the challenge.

"To our knowledge … this kind of stay hasn't happened," Morrisey said. It provides a "strong signal" that the challenges in the appeals court are legally sound.

The states will begin filing briefs with the appeals court Feb. 19, laying out their arguments in the run-up to oral arguments in June.