China's leader-in-waiting Xi Jinping will attend the upcoming 9th China-Asean Expo, in what appears to be a move to further allay speculation over his health and uncertainties over this autumn's leadership transition. Vice-President Xi will take part in the opening ceremony and other activities at the expo in Nanning , the capital city of the southern Guangxi Zhuang Autonomous Region, Foreign Ministry spokesman Hong Lei said. The five-day expo, which is scheduled to start on Friday, will gather foreign leaders from Association of Southeast Asian Nations countries. Professor Zhang Ming, a political scientist at Renmin University in Beijing, said Xi's attendance was aimed at further curbing rumours, particularly in overseas media, about his health and political status. On Wednesday, Xi issued a statement offering condolences to the family of a deceased party veteran, but Zhang said the gesture failed to allay rumours over his health and political status. On Saturday he delivered a 10-minute speech, intended to popularise the study of science, at China Agricultural University. The speech was twice as long as expected, and Zhang said it helped Xi curb speculation and rumours. Prior to Saturday, Xi last appeared in public on September 1, for a speech he delivered at the Central Party School in Beijing. But in the following days, he failed to meet with visiting US Secretary of State Hillary Rodham Clinton and Singaporean Prime Minister Lee Hsien Loong, prompting questions about the 59-year-old's health, and whether he would take over as party chief at the 18th congress, which is likely to take place next month. "The upcoming China-Asean Expo will provide him with a good chance to talk to foreign media," Zhang said. Zhang also said that Xi's political status appears to be guaranteed, after his confidant, Li Zhanshu, replaced Ling Jihua, President Hu Jintao's former chief aide, as director of the General Office of the party's Central Committee early this month. Veteran China-watcher Johnny Lau Yui-siu said the speculation over Xi's health shows that government transparency regarding the health of leaders remains poor and has not improved since the Mao Zedong era.