North Korean leader Kim Jong Un holds a military meeting in Pyongyang, North Korea, in this photo released on March 27, 2019 by North Korea’s Korean Central News Agency (KCNA). Photo: KCNA / via Reuters US President Joe Biden , in Seoul before heading to Japan as part of his first Asia trip as president, had a simple message for North Korea’s Kim Jong Un: “Hello … period,” he told reporters on the last day of his visit to South Korea on Sunday. Biden said he was “not concerned” about new North Korean nuclear tests , which would be the...