The acting U.S. ambassador to China quit over President Donald Trump's decision to exit the Paris Climate agreement, sources told CNN.

David Rank, a career foreign service officer since 1990, resigned from his post in Beijing following Trump's announcement last Thursday. Rank was serving until former Iowa Gov. Terry Branstad arrived to take over as ambassador.

"Mr. Rank made a personal decision," a senior State Department official told CNN. "We appreciate his years of dedicated service to the State Department."

Trump said his decision to exit the pact was due to its unfair environmental standards on American workers and businesses. The agreement was made among representatives from 195 nations in Dec. 2015 to adopt green energy sources, cut down on climate change emissions and limit the rise of global temperature.

"I was elected to represent the citizens of Pittsburgh, not Paris," the president said.

China, the world's largest emitter of man-made carbon, strengthened its promise to the Paris deal and said it would take a leading role in tackling climate change. The country has already overtaken the U.S. in transitioning to renewable energy and last year became the world's top solar generator.

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