Well-known Chinese news site Sina recently reported that the Chinese government refused a request from the U.S. Navy to visit Hong Kong. In the meantime, China also called back the Chinese Naval commander, who was visiting the U.S. and cancelled a high-level military meeting. This was in response to the earlier U.S. sanctions against a high-ranking Chinese military officer. In the past, China does have a history of refusing to allow U.S. Naval vessels to visit Hong Kong – as a way of expressing unhappiness. The spokesperson for the Chinese Ministry of Foreign Affairs commented that China typically evaluates this kind of request on a case by case basis.
Source: Sina, September 25, 2018