and air presence, challenging u.s. naval supremacien ty ein t region. >> cnn's david mckenzie following this story from south korea. i spoke with him earlier. >> rosemary they claim 90% of the south china sea, gee graphically look at the map of the mainland isn't close to some of the disputed island. you have countries. territories, jim mentioned that have claims over certain parts of the south china sea. china says it has an historical precedent for this. looks become to maps for the 40s and earlier saying it in fact claim all of this. they have an unshakeable territorial right over the south china sea. one of the things talked about, status quo. the u.s. and u.s. policy makers saying china is trying to change the status quo by anchoring itself and expanding these island with military assets.