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 Terry Branstad confirmed his decision in a phone call with President Donald Trump last week. It did not give a reason for his departure. 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. He served as Iowa’s Governor from 1983-1999 and from 2011-2017.