A federal appeals court sided with the U.S. Environmental Protection Agency on Friday in an ongoing dispute with Texas and Wyoming over reducing greenhouse gas emissions.

The ruling by the U.S. Court of Appeals for the District of Columbia amounted to a defense of the federal Clean Air Act that has faced repeated challenges from Texas, which leads the nation in greenhouse gas emissions.

Federal environmental regulators have required states to include greenhouse gases when issuing pollution permits since 2011. The EPA took over Texas' permitting program when the state refused to comply, but Texas fought to retain control.

State environmental regulators in Texas called the decision disappointing. Bryan Shaw, chairman of the Texas Commission on Environmental Quality, criticized the EPA for imposing what he called restrictive timelines on states to meet new requirements.

"In light of all of this, it is remarkable that the D.C. Circuit has repeatedly found no harm to the states with respect to EPA's greenhouse gas rules," Shaw said.

The EPA released a statement saying the agency was pleased that the permitting structure was left in place.