The Donald Trump administration has rolled back former President Barack Obama's Clean Power Plan to limit carbon emissions and force the transition toward less polluting forms of energy.
The new directive, dubbed "Accessible Clean Energy" and announced by Environment Protection Agency chief Andrew Wheeler on Wednesday, instructs the individual states to develop their own plans for power plant emission standards but does not include reduction targets for the states, Efe news reported.
Under the new rule, the states will have up to three years to develop plans to reduce power plant emissions and the EPA will have 12 months to review those plans and either approve or deny them.
Wheeler said in formally announcing the plan that the new rule "gives states the regulatory certainty they need to reduce emissions and provide affordable and reliable energy for all Americans".
He added that the new rule also puts an end to the "war on coal" launched by Obama.
The 2015 federal regulation required that carbon emissions from coal-fed power plants be reduced by 32 per cent by 2030 compared with 2005 levels and urged electricity supply companies to adapt to cleaner forms of energy like natural gas, solar power or wind power.
Nevertheless, although it had not entered into force, Obama's plan had already been blocked in court battles in 27 states.
Since he took office in January 2017, Trump has criticised what he has called the excessive number of regulations imposed by the 2009-2017 Obama administration and moved to revitalize the US coal industry.
In addition, the president has expressed skepticism about climate change and global warming despite the warnings issued by the scientific community.
In June 2017, Trump announced that he was withdrawing the US from the Paris Accord, a move that will not become effective until 2020 but which means virtually the end of all climate commitments according to which the US had agreed to reduce greenhouse gas emissions by 26-28 per cent from 2005 levels by 2025.
The measure announced on Wednesday was rejected by environmental protection groups and those fighting against climate change.