Speaking to reporters on her way to Japan, Theresa May four times refused to rule out British action to stop North Korea’s illegal missile launches, as the rogue state threatened to increase its military tests. She called on China to do more to rein in dictator Kim Jong-un, and said such pressure was the key to easing the crisis. A British government source suggested that cyber-warfare might already be being deployed against North Korea, saying to reporters, ‘If we were doing that we certainly wouldn’t be telling you.’ Mrs May landed in Japan on 30 August, a day after a North Korean missile flew over Hokkaido. Her talks with President Shinzo Abe will focus on trade, security, and Kim’s nuclear and ballistic missile programmes.