The Natural Resources Defense Council (NRDC) and the Minnesota Center for Environmental Advocacy have filed a lawsuit challenging a decision by US President Donald Trump to grant two-year air pollution exemptions to eight iron ore mines and processing plants in Minnesota and Michigan. 

The facilities include operations owned by Cleveland-Cliffs and U.S. Steel. The exemptions delay compliance with a 2024 rule limiting toxic emissions, including mercury, issued by the US Environmental Protection Agency under a court order. 

Environmental groups argue the waivers endanger nearby communities, while Trump contended that the 2024 rule burdens the industrial foundation, potentially causing production shutdowns and compromising the national ability to supply steel for defense, energy, and critical manufacturing.