China said on Friday it was "extremely concerned" about suggestion from a top US commander that US ships and aircraft should challenge China's claims in the South China Sea by patrolling close to artificial islands it has built. China's increasingly assertive action to back up its sovereignty claims in the South China Sea have included land reclamation and the construction of ports and air facilities on several reefs in the Spratly Islands. The work has rattled China's neighbors, in particular US ally the Philippines, and raised concern in the United States.

China 'extremely concerned' by proposed US challenge. (2015, September 19). Philippine Daily Inquirer, p. A16.