BEIJING (AP) — The U.S. ambassador to China will step down early next month, ending a three-year tenure marked by a trade war and increasingly bitter relations between the world’s two largest economies. The U.S. Embassy in Beijing says former Iowa Governor Terry Branstad confirmed his decision in a phone call with President Donald Trump last week. It did not give a reason for his departure.

FILE – In this June 28, 2017, file photo, U.S. Ambassador to China Terry Branstad makes comments about pro-democracy activist and Nobel Laureate Liu Xiaobo during a photocall and remarks to journalists at the Ambassador’s residence in Beijing. Branstad appears to be leaving his post, based on tweets by Secretary of State Mike Pompeo. Pompeo thanked Branstad for more than three years of service on Twitter on Monday, Sept. 14, 2020. (AP Photo/Ng Han Guan, File)

Trade relations soured under Trump, and other disputes followed over technology, human rights and the response to the coronavirus pandemic. Branstad became embroiled in a recent controversy when China’s official People’s Daily newspaper rejected an opinion piece by him.