Former foreign ministry spokesman Ma Zhaoxu will become China’s ambassador to the United Nations headquarters in New York, one of the country’s most prestigious overseas posts, according to diplomatic sources. Ma, 54, returned to Beijing last week after a 20-month stint as the country’s top envoy to the UN in Geneva. As China’s point man at the UN headquarters will be at the forefront of a more ambitious and assertive foreign policy under President Xi Jinping.