Japan tells China and Russia it has ‘severe concerns’ over joint air patrol, would "decisively protect" its territories

Japan has told China and Russia it has "severe concerns" over their frequent joint air force activities around Japan's territory, Chief Cabinet Secretary Hirokazu Matsuno said on Thursday.

"We will closely monitor the increasing cooperation between the two countries with a sense of concern," Matsuno, Japan's top government spokesperson, told a regular press conference, adding that Japan would "decisively protect" its territories.