Question for non-United States folks ... Is the adjective/description "US-American" common, or at least familiar to you? I noticed this caption on #wikipedia. (It's better than "USian," I suppose.)
Arguments against the U.S. using "American" as its demonym are duly noted, but unpersuasive. Look, no other country's name contains the word America. And every alternative is awkward.
By the way, do people from South Sudan, the DRC, or Chad criticize the Central African Republic for claiming "Central African" as their demonym? Have they considered "CA-Republican" instead?