The Chosun Ilbo, quoting a high-ranking diplomatic source in Seoul, reports that Japan has told the United States it opposes the extension of South Korean missile ranges.
Presumably this would indicate they wish the Americans to oppose it, too.
South Korean missile ranges are limited to 300km by bilateral agreement with the United States. The Koreans would like to extend this and are discussing the matter with Washington.
The Japanese apparently worry that if South Korean missile ranges are extended to 800km or over, it could put much of Japan within South Korean missile range. Tokyo is 1,160km from Seoul, and Osaka just 848km away.
Japan, meanwhile, has three-stage rockets, which could easily be converted into ICBMs.
Japan is reportedly telling the Americans that should South Korea’s missile capabilities be strengthened significantly, Seoul could engage in independent action against the North.