The Russian president, Vladimir Putin, has warned that the escalating North Korean crisis could cause a “planetary catastrophe” and huge loss of life, and described US proposals for further sanctions on Pyongyang as “useless”. “Ramping up military hysteria in such conditions is senseless; it’s a dead end,” he told reporters in China. “It could lead to a global, planetary catastrophe and a huge loss of human life. There is no other way to solve the North Korean nuclear issue, save that of peaceful dialogue.”