The top U.S. diplomat in China has reportedly stepped down because of President Trump’s policy on climate change. David Rank, the acting U.S. ambassador to China, has “resigned from the foreign service” due to a “personal decision,” a State Department spokesman confirmed Monday. Anna Richey-Allen, a spokeswoman for the department’s East Asia Bureau, did not confirm reports that Rank’s resignation was a direct result of Trump’s decision to withdraw the U.S. from the Paris Agreement. But a senior U.S. official cited by Reuters said earlier reports that Rank quit because he could not bring himself to notify Chinese authorities of Trump’s climate policy were accurate. Trump has faced criticism at home and abroad for his decision to scrap U.S. participation in the agreement, which obliges signatories to cut carbon emissions. The official, who spoke on the condition of anonymity, said Rank announced his decision Monday and was promptly told he’d have to leave his post immediately. Iowa Gov. Terry Branstad is expected to take Rank’s place as ambassador this month.