House Oversight and Accountability Chairman James Comer, R-Ky., is probing the State Department over its apparent coordination with environmental groups pushing to shutter global coal power.

In a letter sent Friday to Secretary of State Antony Blinken, Comer revealed that his committee obtained emails between Special Presidential Envoy for Climate John Kerry’s office and environmental groups like the Natural Resources Defense Council (NRDC) showing extensive communication about plans to oppose coal power. Officials specifically discussed joining the Powering Past Coal Alliance (PPCA), a group the U.S. formally joined in December.

“To meet our goal of 100% carbon pollution-free electricity by 2035, we need to phase out unabated coal, and we urge the world to join us in doing so, while working to grow good-paying clean energy jobs,” Kerry said in a statement on Dec. 2 from the COP28 United Nations climate summit in Dubai.

“Together with the Powering Past Coal Alliance, we will be working to accelerate unabated coal phase-out across the world, building stronger economies and more resilient communities,” he added. “The first step is to stop making the problem worse: stop building new unabated coal power plants.”