Officials denied it at first, then senior government leaders said policy action would be taken — quite a bit of back-and-forth.
The notice has now been posted: https://www.us.emb-japan.go.jp/j/announcement/new-measures-to%20strengthen-border-measures.pdf
The report comes from Reuters, Tokyo, March 30. Japanese authorities have not yet made a formal announcement. Once announced, travelers departing from the U.S. and transiting in Japan on their way back to China will likely be affected. Over the past two days, a large number of Chinese students were stranded in Ethiopia, triggering a wave of public commentary. Fortunately, that issue was specially approved and resolved, and the stranded students have now all returned to China.
If you have upcoming travel that includes a transit in Japan, please watch developments closely. A ban on entry does not necessarily mean a ban on transit, but this is not good news.
Reuters, Tokyo, March 30 - Japan's Asahi Shimbun reported on Monday that the Japanese government will step up its epidemic-control measures and ban entry by foreign nationals arriving from the United States, China, South Korea, and most European countries.The report said that non-Japanese citizens who have been in those areas within the past 14 days will be denied entry. Citing unidentified government sources, Asahi Shimbun also said that Japan may prohibit travel to and from parts of Southeast Asia and Africa.
At present, Japan has only imposed entry bans on South Korea, parts of China, and several European countries, and requires arrivals from the United States, China, and South Korea to self-isolate for two weeks.
There has been no comment from government officials so far.