More than two decades of climate diplomacy produced the Paris Agreement in December 2015. The accord requires the 195 signatories — nearly every country in the world — to create national plans to reduce their greenhouse gas emissions in a bid to mitigate the impact of climate change.

Syria and Nicaragua are the only countries in the U.N. group that are not signatories.

The treaty aims to prevent global temperatures from rising by more than 2 degrees Celsius above pre-industrial levels.

Under President Barack Obama, the United States committed to reducing its greenhouse gas emissions by 26 to 28 percent below 2005 levels by 2025. The Obama administration also pledged $3 billion to a fund established to help developing nations meet their Paris Agreement goals, the largest donation announced to date.

Trump and many of his allies have long dubbed the Paris Agreement a “bad deal” for America. They say it forces the United States to make immediate sacrifices that will hurt the economy, while other countries such as China are allowed to put off action until later.

Sierra Club Executive Director Michael Brune said Trump had ceded the United States’ role in directing climate change efforts to countries like China and India.

“Trump has abandoned the standard of American leadership, turned his back on the what the public and the market demand, and shamelessly disregarded the safety of our families just to let the fossil fuel industry eek out a few more dollars in profits,” he said in a statement.