UPDATE 2-China's August exports unexpectedly shrink as U.S. shipments slump

China's exports unexpectedly fell in August as shipments to the United States slowed sharply, pointing to further weakness in the world's second-largest economy and underlining a pressing need for more stimulus as the Sino-U.S. trade war escalates.Beijing is widely expected to announce more support measures in coming weeks to avert the risk of a sharper economic slowdown as the United States ratchets up trade pressure, including the first cuts in some key lending rates in four years.