Defence Minister Chang Wanquan began his visit to the United States yesterday, accompanied by a delegation that included the commander of the PLA garrison in Hong Kong. The reasons for Lieutenant General Wang Xiaojun's addition to the delegation were not clear. The Hong Kong post is relatively low in the People's Liberation Army hierarchy and the garrison commander's attendance at such a high-level meeting is rare. The Ministry of National Defence provided only broad details of the visit to the US and Canada in a brief statement posted on its website yesterday. Chang was also accompanied by Vice-Admiral Ding Yiping , a deputy commander of the PLA navy, and Lieutenant General Wang Jiurong , deputy commander of the Second Artillery Corps in charge of strategic missiles. Ni Lexiong , director of the Sea Power and Defence Policy Research Institute at Shanghai University of Political Science and Law, speculated that discussions could touch on US port calls to Hong Kong. "US military vessels have sometimes berthed in Hong Kong and the two nations may need to discuss arrangements for future US vessels coming to Hong Kong," Ni said. "Hong Kong has a role to play in the Sino-US military relationship." In April, the US navy hosted PLA officers on tours of three American naval ships visiting Hong Kong. The USS George Washington aircraft carrier battle group visited the city last year. Antony Wong Dong, president of the Macau-based International Military Association, said Wang's inclusion in the trip could be part of an effort to raise Hong Kong's international standing. "The commander is unlikely to give any comment on Hong Kong affairs," Wong said. The trip comes amid rising suspicions between Beijing and Washington over each other's military intentions in the Asia-Pacific region. Both sides, however, have expressed a desire for a "new type of relationship", and in annual high-level talks in Washington last month, pledged to explore a new notification mechanism for major military activities and discuss the rules of behaviour for military air and maritime activities. "Both sides will discuss ways to establish the notification system," Ni said. "And other co-operation, such as joint drills and rescue missions, will also be discussed."