Yomiuri Shimbun says Japan is planning to refit the Izumo-class helicopter destroyers so that it can operate as a floating refueling carrier for American F-35Bs.
By Kaijō Jieitai （海上自衛隊 / Japan Maritime Self-Defense Force） (http://www.mod.go.jp/msdf/formal/jmp/201612.html) [CC BY 4.0], via Wikimedia Commons
“If an [MSDF] aircraft carrier were capable of refueling the U.S. military’s F-35Bs, there definitely would be a demand from the U.S. military, making it a symbol of strengthening the [Japan-U.S.] alliance,” the article quoted a Japanese defense official as saying.
Paragraph 2 of Article 9 of Japan’s Constitution prevent Tokyo from having an aircraft carrier. Buying F-35Bs and deploying them on the Izumo-class could violate the Article.