- Izumo, a helicopter carrier, is being sent by Japan to protect a US supply ship
- The American vessel is thought to be supplying the USS Carl Vinson strike group
- Deployment marks the first time Japan has used new powers allowing its military to carry out actions that are not strictly in self-defense
- Comes as North Korea threatened to carry out a sixth nuclear test at ‘any time’
The 800ft helicopter carrier Izumo left its home port of Yokosuka, south of Tokyo, on Monday to escort the American vessel to the waters off Shikoku, around 400 miles away at the top end of Japan’s south island.