The U.S. Supreme Court on Monday delivered a heavy blow to the Obama administration's environmental protection initiatives by blocking a federal clean air regulation for not properly considering the costs of compliance.

The top court ruled in a 5-4 decision to block the air quality regulation by the Environmental Protection Agency (EPA), which aimed to curb emissions of toxic pollutants from coal-fired power plants, saying the EPA regulation should have taken costs of compliance into consideration in deciding whether to regulate the pollutants.

Though Monday's court decision did not strike down the EPA regulation,it temporarily prevents the agency from imposing rules aimed at limiting emissions of mercury and other toxic pollutants from coal-fired power plants until the EPA reconsiders its rule- making.

The Supreme Court's decision was a victory for a coalition of 20 states and industry groups, who had for long been arguing that the federal government had imposed costs of 9.6 billion dollars annually while the benefits of the regulation was about 6 million U.S. dollars.

After the court ruling, White House spokesman Josh Earnest said the administration was "disappointed" over the decision, adding that the Obama administration was still reviewing the ruling.